[Diffuse interstitial lung disorders caused by the environment and occupation].

Diffuse interstitial lung diseases caused by exogenous factors can be divided into those that arise as a result of a progressive accumulation of (mainly) mineral particles in the lung parenchyma, and those that essentially result from a particular susceptibility of the host for specific agents. The former category consists mainly of silicosis, coal worker's pneumoconiosis and asbestosis, as well as other mineral pneumoconioses. The latter category contains extrinsic allergic alveolitis, which is mainly caused by the inhalation of bio-aerosols, chronic beryllium disease and other sarcoid-like diseases, and hard-metal or cobalt lung.

[Bibliographic study of the effectiveness of preventive measures in occupational asthma].

Having retrieved information from bibliographical searches as well as through a vertical analysis of the health problem, this analysis provided in the article points out the effective prevention strategies and interventions for managing occupational asthma. There is no scientific evidence on a series of protection measures and even less for intervention operationalisation strategies. However, considering the increase of the incidence of the disease and its economic and social consequences, it is critical that the various concerned actors understand the trend of this health problem in order to better comprehend their role in the individual and collective prevention strategies.

Pulmonary toxicity of polyvinyl chloride particles after repeated intratracheal instillations in rats. Elevated CD4/CD8 lymphocyte ratio in bronchoalveolar lavage.

Occupational exposure to polyvinyl chloride (PVC) particles has been associated with interstitial lung disease. Our previous study showed that a single intratracheal instillation of emulsion PVC particles, with or without residual additives, induces acute but transient alveolitis in a dose-dependent manner in rats. The aim of the present study was to investigate the pulmonary response after the administration of the same PVC particles (PVC-E3 and PVC-W3) given in the same cumulative doses (10 and 50 mg/kg BW), but fractionated as seven intratracheal instillations (7 x 1.

Pulmonary toxicity of polyvinyl chloride particles after a single intratracheal instillation in rats. Time course and comparison with silica.

Our previous in vitro studies indicated that emulsion polyvinyl chloride (PVC) particles (PVC-E3), with a mean diameter of 2 microm, exhibited a moderate toxicity in different pulmonary cell cultures. The in vitro cytotoxicity and pro-inflammatory potential of PVC-E3 particles were reduced when the additives had been "washed off" (PVC-W3), indicating that PVC-particle associated toxicity is probably related to the residual additives. In the present study, male Wistar rats (230 +/- 18 g) received a single intratracheal instillation of vehicle, crystalline silica particles [Min-U-Sil, 10 mg/kg body weight (BW)], PVC-E3 (10 or 50 mg/kg BW), or PVC-W3 (10 or 50 mg/kg BW).

Effects of propranolol on xenobiotic enzyme activities in rat type II pneumocytes and alveolar macrophages in vivo.

The accumulation of basic drugs (cationic amphiphilic), such as beta-adrenergic antagonists, by pulmonary tissue is well known. Ring hydroxylation of nonselective beta-adrenergic blocking agent propranolol is mediated mainly by cytochrome P450 (CYP) 2D6 and N-desisopropylation by CYP1A2 in human and rat liver microsomes. In this study, the repeated administration of propranolol resulted in a marked inhibition of hepatic metabolism and an increase in its systemic availability, due to covalent binding of reactive metabolites (formed from 4-OH-propranolol) to liver microsomal P4502D enzymes.

The prevention of occupational asthma.

There is sufficient understanding of the causation of occupational asthma for preventive action to be appropriate. To date, attempts appear to have been largely unsuccessful and this appears to be largely due to nonscientific/technical obstacles. These include the fragmented nature of the disease, its low public and industrial profile, and its comparative rarity in single workplaces.

Propranolol cytotoxicity in rat and human lung in vitro.

Propranolol is a lipophilic nonselective beta blocker mainly eliminated via the liver. The specific architectural arrangement of the mammalian lung favors the filtration of so-called pneumophilic drugs out of the blood and retention within the tissue, as shown in particular for amphetamine, amiodarone, imipramine, chlorpromazine, propranolol and local anesthetics. In the current study we tested in vitro the susceptibility of freshly isolated rat type II pneumocytes (RTII), rat alveolar macrophages (RAM), human alveolar macrophages (HAM) and A549 human lung adenocarcinoma cell line (A549) to propranolol (0.

Validity of methods to predict the respiratory sensitizing potential of chemicals: A study with a piperidinyl chlorotriazine derivative that caused an outbreak of occupational asthma.

A piperidinyl chlorotriazine (PCT) derivative, used as a plastic UV-stabilizer, caused an outbreak of occupational asthma. We verified, in BALB/c mice, the sensitizing potential of PCT in comparison to a known respiratory sensitizer (toluene diisocyanate [TDI]) and a known dermal sensitizer (oxazolone), using three different methods in order to evaluate the validity of current models of sensitization. These included the local lymph node assay (LLNA) and the mouse IgE test.

Air pollution and thrombosis: an experimental approach.

Air pollution is associated with cardiovascular mortality. Inhaled ultrafine particles translocate into the blood. Amine-polystyrene ultrafine particles significantly enhance experimental thrombus formation in a damaged hamster vessel and shorten the closure time in the Platelet Function Analyser.

Pulmonary inflammation and thrombogenicity caused by diesel particles in hamsters: role of histamine.

Short-term increases in particulate air pollution are associated with increased incidence of cardiovascular events. Previously, we showed that intratracheally instilled diesel exhaust particles (DEPs) are prothrombotic. Here, we investigated the time course and the mechanisms.

In vivo genotoxicity of hard metal dust: induction of micronuclei in rat type II epithelial lung cells.

Inhalation of hard metal dust (WC-Co particles) has been associated with an increased risk for lung cancer in occupational settings. In vitro, WC-Co was genotoxic in human lymphocytes producing DNA strand breaks and micronuclei. The aim of the present study was to evaluate the in vivo genotoxic effects of WC-Co dust in rat type II pneumocytes.

Effect of polystyrene particles on lung microvascular permeability in isolated perfused rabbit lungs: role of size and surface properties.

The aim of this study was to investigate the role of particle number, total surface area, mass and surface chemical groups in (K(f,c)) changes. The lung effects of four different fine (110 nm) and ultrafine (24 nm) polystyrene particles have been tested in an isolated perfused rabbit lung model. Pulmonary microvascular permeability (K(f,c)) modifications were measured in response to intratracheal particle challenge.

Media warnings about environmental pollution facilitate the acquisition of symptoms in response to chemical substances.

Objective: Previous studies showed that somatic symptoms can be acquired in response to chemical substances using an associative learning paradigm, but only when the substance was foul smelling and not when it smelled pleasant. In this study, we investigated whether warnings about environmental pollution would facilitate acquiring symptoms, regardless of the pleasantness of the smell.

Method: One group received prior information framing the study in the context of the rapidly increasing chemical pollution of our environment.

Diesel exhaust particles in lung acutely enhance experimental peripheral thrombosis.

Background: Pollution by particulates has consistently been associated with increased cardiovascular morbidity and mortality, but a plausible biological basis for this association is lacking.

Methods And Results: Diesel exhaust particles (DEPs) were instilled into the trachea of hamsters, and blood platelet activation, experimental thrombosis, and lung inflammation were studied. Doses of 5 to 500 micro g of DEPs per animal induced neutrophil influx into the bronchoalveolar lavage fluid with elevation of protein and histamine but without lactate dehydrogenase release.

Role of residual additives in the cytotoxicity and cytokine release caused by polyvinyl chloride particles in pulmonary cell cultures.

Occupational exposure to polyvinyl chloride (PVC) dust has been linked to pulmonary disease. The aim of the present study was to investigate, in vitro, the role of additives in the cytotoxicity and the release of inflammatory mediators caused by PVC particles in different cells. We compared two types of emulsion PVC particles (E3 and E8) with their washed (hence, "additive-free") counterparts (W3 and W8).

Size effect of intratracheally instilled particles on pulmonary inflammation and vascular thrombosis.

Particulate air pollution is associated with cardiorespiratory effects and ultrafine particles (UFPs, diameter < 100 nm) are believed to play an important role. We studied the acute (1 h) effect of intratracheally instilled unmodified (60 nm), negatively charged carboxylate-modified (60 nm), or positively charged amine-modified (60 or 400 nm) polystyrene particles on bronchoalveolar lavage (BAL) indices and on peripheral thrombosis in hamster. The latter was assessed by measuring the extent of photochemically induced thrombosis in a femoral vein via transillumination.

Familial and environmental determinants for wheezing and asthma in a case-control study of school children in Palestine.

Background: Our prevalence study on Palestinian school children aged 6-12 years showed lower rates for asthma and asthma symptoms than economically developed and industrialized countries. Reasons for such differences are largely unknown, and could possibly be related to different environmental and lifestyle factors.

Objective: To investigate familial, early life exposures and indoor environmental determinants for asthma in children in Palestine.

Kinetics of an intratracheally administered chromium catalyst in rats.

Chromium-based catalysts are used for the synthesis of polyethylene, but little is known about the hazard and biomonitoring possibilities of this type of chromium for workers who may be occupationally exposed to such compounds. Therefore, the bioavailability and toxicokinetics of chromium were studied in male Wistar rats after a single intratracheal instillation (2 ml/kg body weight) of various doses (1, 5, or 25 mg/kg body weight) of the catalyst (approximately 1% chromium bound to an amorphous silica matrix), either before (CAT-Cr[III]) or after (CAT-Cr[VI]) heat treatment. The results were compared with those of equivalent amounts of two chromium salts (CrCl(3) and K(2) Cr(2) O (7).

Geographical variations of asthma and asthma symptoms among schoolchildren aged 5 to 8 years and 12 to 15 years in Palestine: the International Study of Asthma and Allergies in Childhood (ISAAC).

Background: Many studies demonstrated the existence of geographic differences, within and between countries, in the prevalence of asthma, rhinitis, and eczema. However, in Palestine, there are no comprehensive Palestinian data to compare with those from other regional and international centers.

Objective: To describe the prevalence of asthma and asthma symptoms in schoolchildren in two districts (Ramallah and North Gaza) in Palestine.

Ultrafine particles affect experimental thrombosis in an in vivo hamster model.

Particulate air pollution is associated with cardiovascular morbidity and mortality. To investigate this association, we studied the effect of ultrafine (60 nm) polystyrene particles on thrombus formation in a hamster model after intravenous and intratracheal administration of unmodified, carboxylate-polystyrene, or amine-polystyrene particles. Unmodified particles had no effect on thrombosis up to 5 mg/kg.