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1.
J Prev Med Hyg ; 59(1): E8-E13, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29938234

ABSTRACT

INTRODUCTION: Measles continues to be a major public health issue worldwide, with high morbidity and mortality rates. The disease remains endemic in 14 European countries, including Italy where, from 2013 to 2016, over 5,000 cases have been reported. In 2017, many Italian regions, including Sicily, have reported many cases of measles. In this study, we described the latest measles outbreak in the city of Messina, from 1st February to 31st August 2017. METHODS: We considered all reported measles cases that came to the "Public Health, Epidemiology and Preventive Medicine" Operative Unit of the Messina Provincial Health Agency Prevention Department, which receives all reported cases of measles in the Messina province. RESULTS: From 1st February to 31st August 2017, a total of 59 measles cases were reported, of which 44 were confirmed, nine were classified as possible, four were probable and two cases were discarded. Of the 57 possible, probable and confirmed cases, 31 (54%) were males and 26 (46%) were females. Moreover, 54 (95%) had not been previously vaccinated while the remaining cases had documented evidence of one (two cases) or two doses (one case). Genotype B3 was identified in 39/44 cases (88,6%) by the regional reference laboratory in Palermo. CONCLUSIONS: Despite the development of an effective vaccination, unfortunately measles continues to threaten the lives of millions of children worldwide each year. The suboptimal immunization level in Italy has led to an increase in the transmission of measles with detrimental effects on both public health and ongoing measles elimination efforts.


Subject(s)
Disease Outbreaks , Measles/epidemiology , Adolescent , Adult , Child , Child, Preschool , Databases, Factual , Female , Humans , Infant , Male , Measles/prevention & control , Sicily/epidemiology , Vaccination Coverage , Young Adult
3.
Eur Respir J ; 37(2): 299-309, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20530043

ABSTRACT

The aim of this study was to investigate the modulation of an asthmatic response by titanium dioxide (TiO2) or gold (Au) nanoparticles (NPs) in a murine model of diisocyanate-induced asthma. On days 1 and 8, BALB/c mice received 0.3% toluene diisocyanate (TDI) or the vehicle acetone-olive oil (AOO) on the dorsum of both ears (20 µL). On day 14, the mice were oropharyngeally dosed with 40 µL of a NP suspension (0.4 mg·mL⁻¹ (∼0.8 mg·kg⁻¹) TiO2 or Au). 1 day later (day 15), the mice received an oropharyngeal challenge with 0.01% TDI (20 µL). On day 16, airway hyperreactivity (AHR), bronchoalveolar lavage (BAL) cell and cytokine analysis, lung histology, and total serum immunoglobulin E were assessed. NP exposure in sensitised mice led to a two- (TiO2) or three-fold (Au) increase in AHR, and a three- (TiO2) or five-fold (Au) increase in BAL total cell counts, mainly comprising neutrophils and macrophages. The NPs taken up by BAL macrophages were identified by energy dispersive X-ray spectroscopy. Histological analysis revealed increased oedema, epithelial damage and inflammation. In conclusion, these results show that a low, intrapulmonary doses of TiO2 or Au NPs can aggravate pulmonary inflammation and AHR in a mouse model of diisocyanate-induced asthma.


Subject(s)
Asthma/chemically induced , Asthma/physiopathology , Gold/adverse effects , Lung/physiopathology , Nanoparticles/adverse effects , Titanium/adverse effects , Toluene 2,4-Diisocyanate/toxicity , Animals , Bronchial Hyperreactivity , Bronchoalveolar Lavage Fluid , Disease Models, Animal , Eosinophils , Immunoglobulin E/blood , Macrophages , Male , Mice , Mice, Inbred BALB C , Neutrophils , Pulmonary Edema/chemically induced , Pulmonary Edema/physiopathology
4.
Breast Cancer Res Treat ; 124(3): 667-75, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20213084

ABSTRACT

New drugs with anti-tumor activity, also able to modify the expression of selected molecules, are under evaluation in breast cancer which is becoming resistant to conventional treatment, or in metastatic disease. The sodium-iodide symporter (NIS), which mediates iodide uptake into thyroid cells, and is the molecular basis of radioiodine imaging and therapy in thyroid cancer, is also expressed in a large portion of breast tumors. Since NIS expression in breast cancer is not sufficient for a significant iodide uptake, drugs able to induce its expression and correct function are under evaluation. In the present study, we report for the first time that the pan-deacetylase (DAC) inhibitor LBH589 (panobinostat) significantly induced NIS, both as mRNA and as protein, through the increase of NIS promoter activity, with the final consequence of obtaining a significant up-take of iodide in MCF7, T47D, and MDA-MB231 breast cancer cells. Moreover, we observed that LBH589 causes a significant reduction in cell viability of estrogen-sensitive and -insensitive breast cancer cells within nanomolar range. The anti-tumor effect of LBH589 is sustained by apoptosis induction and cell cycle arrest in G(2)/M. In conclusion, our data suggest that LBH589 might be a powerful tool in the management of breast cancer due to its multiple effects and support a potential application of LBH589 in the diagnosis and treatment of this disease.


Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/metabolism , Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Symporters/metabolism , Apoptosis/drug effects , Biological Transport , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Cycle/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Indoles , Inhibitory Concentration 50 , Iodine Radioisotopes/metabolism , Panobinostat , RNA, Messenger/metabolism , Symporters/genetics , Transfection , Up-Regulation
5.
Chemosphere ; 72(9): 1340-6, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18555515

ABSTRACT

Epidemiological and experimental studies have underlined that exposure to particulate matter (PM) leads mainly to airway inflammation, but the roles of particle size and chemical composition associated to such adverse health outcomes need to be better investigated. This study was performed to validate novel strategies of particle sampling, recovery and cell exposure in order to evaluate the pro-inflammatory potential of fine and ultrafine particles from a fractionated aerosol. Samplings of Paris background aerosols using 13-stage low pressure impactors (0.03-10 microm) gave bimodal mass distributions with an accumulation mode centered on a median diameter of 0.42 microm and a coarse one on 3.25 microm. PM 1 accounted for 70% and PM 0.1 for 12% of PM 10. The latter mainly comprised carbon-chained aggregates. The development of an efficient and reproducible method to recover fine (PM 1-0.1) and ultrafine (PM 0.1-0.03) particulate matter has permitted experimental comparison of the impact of such particles on human bronchial epithelial cells (HBECs). In this study we have compared the relative effects of fine and ultrafine particles at non-cytotoxic concentrations over 24h on the production of the pro-inflammatory cytokine GM-CSF by HBECs. Combining two cell exposure strategies to the size-fraction particles according to either their proportion (isovolume exposure) or their quantity in the aerosol (isomass exposure), we showed that both ultrafine and fine particles induced a concentration-dependent GM-CSF release by HBECs which is significant from 1 microg cm(-2). In conclusion, short duration samplings using 13-stage impactors enable to obtain size-resolved PM in sufficient quantities to carry out toxicological investigations. These findings are promising in view to conduct a more intensive study joining chemical and toxicological assays.


Subject(s)
Inflammation/chemically induced , Particulate Matter/toxicity , Aerosols/analysis , Aerosols/toxicity , Bronchi/drug effects , Cell Survival/drug effects , Cells, Cultured , Endpoint Determination , Epithelial Cells/drug effects , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Inflammation/pathology , Paris , Particle Size , Reproducibility of Results
6.
J Clin Invest ; 108(12): 1817-24, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11748265

ABSTRACT

In animal models of asthma, interleukin-13 (IL-13) induces goblet cell metaplasia, eosinophil infiltration of the bronchial mucosa, and bronchial hyperreactivity, but the basis of its effects on airway epithelia remain unknown. Lesions of the epithelial barrier, frequently observed in asthma and other chronic lung inflammatory diseases, are repaired through proliferation, migration, and differentiation of epithelial cells. An inflammatory process may then, therefore, influence epithelial regeneration. We have thus investigated the effect of IL-13 on mucociliary differentiation of human nasal epithelial cells in primary culture. We show that IL-13 alters ciliated cell differentiation and increases the proportion of secretory cells. IL-13 downregulates the actin-binding protein ezrin and other cytoskeletal components. IL-13 also impairs lateral cell contacts and interferes with the apical localization of ezrin seen in differentiated ciliated cells. In addition, an IL-4 antagonistic mutant protein (Y124D), which binds to the IL-4 receptor alpha subunit, a common chain of IL-4 and IL-13 receptors, inhibits IL-13's effects. IL-13 also decreases ciliary beat frequency in a time- and dose-dependent manner. These results suggest that, in human allergic asthmatic responses, IL-13 affects both ciliated and secretory cell differentiation, leading to airway damage and obstruction.


Subject(s)
Asthma/etiology , Bronchi/drug effects , Interleukin-13/pharmacology , Bronchi/cytology , Cell Differentiation/drug effects , Cell Polarity , Cells, Cultured , Cilia/drug effects , Cilia/physiology , Cytoskeletal Proteins , Dose-Response Relationship, Drug , Epithelial Cells/drug effects , Epithelial Cells/physiology , Humans , Interleukin-4/physiology , Mucin-2 , Mucins/genetics , Mucous Membrane/cytology , Mucous Membrane/drug effects , Phosphoproteins/analysis
7.
Nanotoxicology ; 9 Suppl 1: 118-32, 2015 May.
Article in English | MEDLINE | ID: mdl-25923349

ABSTRACT

In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project ( www.nanotest-fp7.eu ) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed.


Subject(s)
Nanomedicine/methods , Nanoparticles/toxicity , Toxicity Tests/methods , Humans , In Vitro Techniques/standards , Toxicity Tests/standards
8.
Eur J Cell Biol ; 77(3): 205-13, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9860136

ABSTRACT

Primary cultures of rabbit tracheal epithelial (RbTE) cells have been performed in two different ways. Quantitative analysis of both proliferative capacities and ciliated differentiation process were carried out using epithelial cell cultures from tracheal explants and from dissociated tracheal epithelial cells in air-liquid interface conditions. We show that both alpha- and beta-tubulins from RbTE cells are polyglutamylated and that this posttranslational modification is restricted to cilia axonemes and centrioles of non-ciliated cells. A monoclonal antibody raised against polyglutamylated tubulins was used to quantify the proportion of ciliated cells. Even though epithelial cells from outgrowths obtained by the explant technique highly proliferated during the first days of culture, no ciliated differentiation occurred. On the other hand, using air-liquid interface conditions after proliferation of dissociated cells, we could observe and quantify a ciliated cell differentiation in vitro by both Western blot and flow cytometric analysis. The specific detection and quantification of ciliated cells open the way for the biochemical and molecular characterization of centriolar components during ciliated differentiation.


Subject(s)
Cilia/metabolism , Trachea/cytology , Animals , Blotting, Western , Cell Count , Cell Culture Techniques , Cell Differentiation , Cell Division , Cells, Cultured , Cilia/chemistry , Epithelial Cells/chemistry , Epithelial Cells/cytology , Epithelial Cells/metabolism , Flow Cytometry , Fluorescent Antibody Technique, Indirect , Polyglutamic Acid/analysis , Rabbits , Trachea/chemistry , Trachea/metabolism , Tubulin/analysis
9.
Environ Health Perspect ; 101(5): 436-42, 1993 Oct.
Article in English | MEDLINE | ID: mdl-8119255

ABSTRACT

Environmental mineral particles such as asbestos are responsible for numerous respiratory diseases. In addition to effects related to their geometry, particles are now assumed to act by triggering an oxidative stress process. Iron-containing particles, in particular, can produce oxygen-activated species by oxidizing their iron. To evaluate the involvement of iron-containing particles in respiratory diseases, three mineral particles (chrysotile, nemalite, and hematite) were tested in primary cultures of tracheal epithelium. Because of the ciliary beat, the three mineral particles were quickly concentrated at the periphery of the mucociliary epithelium, reconstituted in vitro where they induced cellular lesions. Endocytosis of the three types of particles was observed. Cytotoxicity studies have indicated that among the tested particles, the most cytostatic after 24 hr of treatment was the one that contained more Fe2+ available on the surface, nemalite. Moreover, the effect of nemalite was reduced by pretreatment with desferrioxamine. As mineral particles, especially asbestos, are suspected to induce squamous metaplasia, we chose to study two specific transformations of the epithelium: the expression of cytokeratin-13 and the formation of cross-linked envelopes. Under our culture conditions, nemalite and chrysotile increased the expression of the cytokeratin-13, a specific marker of squamous metaplasia, whereas nemalite was the only particle able to strongly induce the formation of cross-linked envelopes. Nemalite was the most cytostatic particle and the most efficient at inducing squamous metaplasia. Measures of oxidizing power by electron-spin resonance revealed that nemalite produced the most oxygen-activated species.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Asbestos/toxicity , Ferric Compounds/toxicity , Iron/toxicity , Stress, Physiological/chemically induced , Trachea/drug effects , Animals , Cells, Cultured , Electron Spin Resonance Spectroscopy , Epithelial Cells , Epithelium/drug effects , Free Radicals , Metaplasia/chemically induced , Oxidation-Reduction , Rabbits , Stress, Physiological/pathology , Trachea/cytology
10.
Biomaterials ; 22(3): 195-200, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11197494

ABSTRACT

To study the biocompatibility and the biodegradation rate in vivo of new intravitreal implants made with three different hyaluronic acid esters: Hyaff7, Hyaff11 and Hyaff11p75 (100% ethyl ester, 100 and 75% benzyl esters, respectively), the plugs were implanted through a sclerotomy at 3.5 mm from the limbus of rabbit eyes. In order to evaluate the in vivo biodegradation the shaft diameter of the plugs was measured by ultrasound biomicroscopy. Slit lamp microscopy, ophthalmoscopy and ERG were performed periodically. The effects of the implants on ocular tissues were also evaluated histologically. All the plugs showed a good biocompatibilitv. Plugs of both the total esters, Hyaff7 and Hyaff11, were found to undergo a slow dissolution process for 60 and 150 days, respectively. The partial benzyl ester, Hyaff11p75, was completely reabsorbed after 15 days. Analysis of variance showed a high correlation between biodegradation rate and the time of resorption (F = 90.5; p < 0.001). The biodegradation rate of each implant is related to the chemical structure of the three types of Hyaff (F = 4.51; p = 0.005). The present data suggest that intravitreal implants based on hyaluronic acid esters represent useful biocompatible and biodegradable devices for a potential drug delivery system in the treatment of posterior segment ocular diseases.


Subject(s)
Biocompatible Materials , Drug Implants , Hyaluronic Acid/administration & dosage , Vitreous Body , Animals , Biodegradation, Environmental , Male , Rabbits
11.
Toxicol Sci ; 54(1): 212-21, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10746948

ABSTRACT

The present study was undertaken to find potent molecules against the toxicity of nitrogen mustard mechlorethamine (HN2) on respiratory epithelial cells, using a human bronchial epithelial cell line (16HBE14o-) as an in vitro model. The compounds examined included inhibitors of poly(ADP-ribose) polymerase (PARP), sulfhydryl-group donors as nucleophiles, and iron chelators and inhibitors of lipid peroxidation as antioxidants. Their effectiveness was determined upon observance of metabolic dysfunction induced by HN2 following a 4-h exposure, using (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction and ATP-level assays as indicators. Moreover, the fluorescent probe, monobromobimane (mBBr), and 2',7'-dichlorofluorescin-diacetate (H2DCF-DA) were used to assess intracellular sulfhydryl and peroxide level modifications by flow cytometry, respectively, following a 3-h exposure. At last, cell death was assessed by flow cytometry using the propidium iodide (PI)-dye-exclusion assay following 24-h exposure. PARP inhibitors (niacinamide, 3-aminobenzamide, 6(5H)-phenanthridinone), and two sulfhydryl-group donors (N-acetylcysteine, WR-1065) were found to be effective in preventing HN2-induced metabolic dysfunction when added in immediate or delayed treatment with HN2. Only N-acetylcysteine, however, was found to prevent cell death induced by HN2, though it must be present at the time of the HN2 challenge. Flow cytometric measurements of intracellular sulfhydryl levels strongly suggested that N-acetylcysteine and WR-1065 are preventive in alkylation of cellular compounds, mainly by direct extracellular interaction with HN2. PARP inhibitors prevent secondary deleterious effects induced by HN2, considering metabolism dysfunction as the endpoint. Elsewhere, the oxidative stress appears to be a side effect in HN2 toxicity only upon considering the inefficiency of several antioxidants.


Subject(s)
Antineoplastic Agents/toxicity , Bronchi/cytology , Cell Survival/drug effects , Epithelial Cells/drug effects , Mechlorethamine/analogs & derivatives , Prodrugs/toxicity , Sulfoxides/toxicity , Adenosine Triphosphate/metabolism , Bronchi/drug effects , Cell Line , Enzyme Inhibitors/pharmacology , Flow Cytometry , Humans , Iron Chelating Agents/pharmacology , Lipid Peroxidation/drug effects , Mechlorethamine/toxicity , Oxidative Stress , Poly(ADP-ribose) Polymerase Inhibitors , Sulfhydryl Compounds/metabolism , Sulfhydryl Reagents/toxicity , Tetrazolium Salts , Thiazoles
12.
Toxicol Sci ; 58(1): 153-60, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11053552

ABSTRACT

The aim of this study was to test the efficacy of several candidate molecules against sulfur mustard (SM) and nitrogen mustard (HN2) using a human bronchial-epithelial cell line (16HBE14o-). Candidate molecules were chosen on the basis of the known cytotoxicity mechanisms of mustards or their efficacy previously observed on other cellular models. It included the sulfhydryl-containing molecules N-acetyl-cysteine (NAC) and WR-1065, the nucleophile hexamethylenetetramine (HMT), the energy-level stabilizer niacinamide (NC), the antioxidant dimethylthiourea (DMTU), L-arginine analogues such as L-thiocitrulline (L-TC) and L-nitroarginine methyl ester (L-NAME), and the anti-gelatinase doxycycline (DOX). Their efficacy was determined using 2-(4-[3-iodophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2Htetrazolium (WST-1) reduction by viable cells 24 h after initial exposure to 100 microM HN2 or SM. On individual immediate cotreatment, some molecules exhibited selective protection against only one mustard, such as DMTU and WR-1065 against HN2 and DOX against SM, whereas NAC and L-TC were effective against both SM and HN2 cytotoxicity. However, as the level of protection against SM was always weak compared to HN2, several combinations were investigated against SM to improve the protection. The effective combinations (L-TC + DOX, NAC + DOX, NAC + DMTU, NAC + HMT, NC + DOX) combined agents, reducing the bioavailability of the mustard with compounds possibly acting on the consequences of alkylation. One of these combinations, NAC + DOX, appeared to be the most interesting, as these agents are already used in human therapy. It exhibited good efficacy in delayed cotreatment (up to 90 min) against SM.


Subject(s)
Bronchi/drug effects , Citrulline/analogs & derivatives , Cytoprotection/drug effects , Mechlorethamine/toxicity , Mustard Gas/toxicity , Protective Agents/pharmacology , Thiourea/analogs & derivatives , Acetylcysteine/pharmacology , Bronchi/cytology , Cells, Cultured , Citrulline/pharmacology , Dose-Response Relationship, Drug , Doxycycline/pharmacology , Drug Combinations , Drug Interactions , Epithelial Cells/cytology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Humans , Mercaptoethylamines/pharmacology , Methenamine/pharmacology , NG-Nitroarginine Methyl Ester/pharmacology , Niacinamide/pharmacology , Radiation-Protective Agents/pharmacology , Tetrazolium Salts/metabolism , Thiourea/pharmacology
13.
J Cataract Refract Surg ; 25(9): 1263-9, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10476512

ABSTRACT

PURPOSE: To evaluate the long-term visual results and variability in contrast sensitivity in patients with heparin-surface-modified (HSM) diffractive bifocal intraocular lenses (IOLs). SETTING: Institute of Ophthalmology, University of Catania, Italy. METHODS: In this prospective study, visual acuity (distance and near) and contrast sensitivity were measured in 35 patients who had phacoemulsification with bifocal diffractive IOL (model 811E, Pharmacia) implantation. Patient satisfaction was also evaluated using a questionnaire. Mean follow-up was 20 months (range 18 to 24 months). RESULTS: At the last examination, mean distance visual acuity was 0.79 +/- 0.2 (SD) without correction and 1.0 +/- 0.15 with best correction. Mean uncorrected near visual acuity was J1.6 +/- J0.77 and with best distance correction, J1.19 +/- J0.49. No statistically significant changes in visual acuity were evident at the last follow-up (Student t test). No changes were found in contrast sensitivity reduction over time, nor were late postoperative complications noted. Overall patient satisfaction was rated as good by 94.3% of patients with best distance correction. CONCLUSIONS: The diffractive bifocal HSM IOL provided good visual performance for distance and near over time. In relation to the low rate of postoperative complications, the slight contrast sensitivity reduction was stable during follow-up.


Subject(s)
Contrast Sensitivity/physiology , Lens Implantation, Intraocular , Phacoemulsification , Visual Acuity/physiology , Adult , Coated Materials, Biocompatible , Female , Follow-Up Studies , Humans , Lenses, Intraocular , Male , Middle Aged , Patient Satisfaction , Prospective Studies , Surveys and Questionnaires
14.
Toxicol Lett ; 14(3-4): 143-9, 1982 Dec.
Article in English | MEDLINE | ID: mdl-6188240

ABSTRACT

Acrolein, a potent cilioinhibitor of cigarette smoke was tested on synchronously dividing cultures. Mitosis could be blocked whenever the addition of acrolein was made during the cell cycle but this effect was totally reversible (between 0.06 microgram/ml to 1 microgram/ml). Nucleic acid syntheses were more affected than protein syntheses but the syntheses were only delayed and they resumed simultaneously during the same cycle.


Subject(s)
Acrolein/toxicity , Aldehydes/toxicity , Cell Cycle/drug effects , Cell Division/drug effects , Cell Nucleus/metabolism , Chlorophyta/cytology , Chlorophyta/drug effects , Chloroplasts/metabolism , DNA/biosynthesis , Plant Proteins/biosynthesis , RNA/biosynthesis
15.
Toxicol Lett ; 96-97: 245-51, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9820674

ABSTRACT

A model of rabbit tracheal epithelial (RTE) cells in vitro was developed in order to investigate the effects, on the airway epithelium, of reactive oxygen species (ROS) generated by H2O2 in association or not in association with Fe2+. The immediate consequence of a 24 h exposure of RTE cells to an oxidative stress was an increase in catalase activity whereas superoxide dismutase activity was not modified. A latter consequence of a chronic ROS insult was the induction of a repair mechanism which led to squamous metaplasia (SM). SM is characterized by a stratification of the epithelium, the expression of the cytokeratin 13 and the appearance of cells with cross-linked envelopes. Reversible modifications between mucociliary and squamous phenotype are modulated by retinoids. The action of retinoids is selective: metaplasia is inhibited by agonists of RAR alpha and beta receptors and not by an agonist of RAR gamma receptors.


Subject(s)
Oxidative Stress/physiology , Retinoids/pharmacology , Trachea/physiology , Animals , Catalase/metabolism , Cells, Cultured , Epithelial Cells/drug effects , Epithelial Cells/pathology , Epithelial Cells/physiology , Hydrogen Peroxide/metabolism , Hydrogen Peroxide/toxicity , Ligands , Metaplasia , Rabbits , Reactive Oxygen Species/metabolism , Receptors, Retinoic Acid/classification , Receptors, Retinoic Acid/metabolism , Retinoids/metabolism , Sensitivity and Specificity , Superoxide Dismutase/metabolism , Trachea/drug effects , Trachea/pathology
16.
Toxicol Lett ; 88(1-3): 39-44, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8920715

ABSTRACT

We tested the hypothesis according to which mineral particles containing iron would be able to produce cytotoxic-ROS. We approached this problem in vitro using primary cultures of rabbit tracheal epithelial cells. The oxidizing power of three mineral particles, i.e. nemalite, chrysotile and hematite, has been evaluated for their capacity to induce lipid peroxidation, and to activate intra-cellular anti-oxidant enzymes. The results show that nemalite and chrysotile which contain Fe2+ have a strong oxidizing power, inducing an oxidative stress on airway epithelial cells, whereas hematite, the Fe3+ containing particles, is without effect.


Subject(s)
Asbestos, Serpentine/toxicity , Ferric Compounds/toxicity , Magnesium Hydroxide/toxicity , Oxidative Stress/physiology , Trachea/cytology , Animals , Catalase/drug effects , Catalase/metabolism , Cell Membrane/drug effects , Cells, Cultured , Epithelial Cells , Epithelium/drug effects , Lipid Peroxidation/drug effects , Malondialdehyde/analysis , Malondialdehyde/metabolism , Rabbits , Reactive Oxygen Species/physiology , Superoxide Dismutase/drug effects , Superoxide Dismutase/metabolism , Trachea/drug effects
17.
Cornea ; 16(6): 639-44, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9395873

ABSTRACT

PURPOSE: Our study was designed to calculate central and peripheral corneal thickness in patients affected with early stages of keratoconus and in normal subjects using ultrasound biomicroscopy (UBM). To obtain an objective and reliable assessment of the corneal thinning in affected eyes, we developed a keratoconus index (KI) by means of the UBM measurements. METHODS: By means of the commercial version of the ultrasound biomicroscope (system model 840; Zeiss-Humphrey Instruments, San Leandro, CA, USA) using a 50-MHz probe, we studied 30 normal and affected eyes. In keratoconic eyes, we measured the thinnest corneal thickness (TCT) at the apex of the conus and at four peripheral sites at a distance of 2.5 mm from the central site (peripheral corneal thickness: PCT). The same procedure was performed in the normal eyes. To obtain an objective and reliable assessment of the corneal thinning, we calculated the ratio between the mean PCT and the mean TCT (Keratoconus Index: KI = PCT/TCT), in keratoconic eyes. In normal eyes, the KI was calculated on the basis of the ratio between the mean PCT and the mean central corneal thickness (CCT). RESULTS: In keratoconic eyes, the mean corneal thickness at the thinnest part of the conus was significantly different from the CCT in normal patients (Student's t test, p < 0.001). The peripheral measurements were not significantly different from keratoconic and normal eyes. The mean KI was 1.482 (SD, 0.095) in the keratoconic eyes, whereas it was 1.189 (SD, 0.086) in the normal subjects. The statistical analysis of the KI calculated on the basis of the UBM measurements showed that the KI values are significantly different from healthy subjects and from keratoconic patients (Student's t test, p < 0.001). CONCLUSIONS: UBM can be considered a useful tool in the study of keratoconus. We believe that calculation of the KI by means of UBM gives the possibility of obtaining an objective assessment of corneal thinning. Therefore this parameter can be useful in the staging and in the follow-up of these patients.


Subject(s)
Cornea/diagnostic imaging , Keratoconus/diagnostic imaging , Adolescent , Adult , Evaluation Studies as Topic , Female , Humans , Image Processing, Computer-Assisted , Keratoconus/complications , Male , Middle Aged , Sensitivity and Specificity , Ultrasonography
18.
Toxicol In Vitro ; 11(5): 695-702, 1997 Oct.
Article in English | MEDLINE | ID: mdl-20654373

ABSTRACT

The aim of this in vitro study was to characterize the early effects of short-term exposure to low concentrations of mechlorethamine (HN2), a nitrogen mustard, on rabbit tracheal primary cultures. Marked inhibition of cell growth was observed without recovery until 14 days after the treatment with sublethal doses of HN2. Cell detachment associated with rearrangement of the cytoskeletal proteins was also noted as early as 1 hr after treatment. Moreover, cells treated with HN2 at the sublethal dose of 50 mum (LC(10)) for 1 hr showed early lipid peroxidation and cellular membrane damage. This was correlated with a significant increase in the activities of antioxidant enzymes associated with an increase in glutathione content. These early events appeared several hours before arrest of the cell cycle progression. On the other hand, long-term treatment with HN2 at a sublethal dose led to modification of cytokeratin expression and appeared to induce squamous metaplasia.

19.
Toxicol In Vitro ; 7(4): 373-9, 1993 Jul.
Article in English | MEDLINE | ID: mdl-20732217

ABSTRACT

A simple method has been developed to measure epithelial barrier alteration, in order to evaluate the irritant effect of inhaled compounds on the respiratory tract. In vitro primary cell cultures from rabbit tracheal epithelium were grown on permeable filters and used to study the effect of two pollutants-acrolein and parathion-on epithelial barrier integrity. The transepithelial potential difference and [(14)C]mannitol permeability were measured. Acrolein specifically injured the tight junctions and therefore increased transepithelial permeability. Parathion did not produce any alteration of the epithelial barrier but the results suggest alteration of ionic transport.

20.
Toxicol In Vitro ; 5(5-6): 499-502, 1991.
Article in English | MEDLINE | ID: mdl-20732064

ABSTRACT

Cytotoxic assays have been carried out to evaluate toxic effects of acrolein, mechlorethamin, parathion and paraoxon, using primary cultures of rabbit tracheal epithelium obtained by the explant outgrowth technique. The effect of drug exposure was first evaluated by the tetrazolium salt assay, neutral red uptake and release of cellular lactate dehydrogenase. These assays, previously developed for cell line cultures, were adapted to our model. In addition, we present in this paper an easy and rapid method to evaluate the effect of chemicals on cell proliferation. This was performed using an image analysis method, and was found to be the most sensitive marker to determine the acute toxicity of chemicals.

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