A first French assessment of population exposure to tetrachloroethylene from small dry-cleaning facilities.

UNLABELLED: Used as a solvent in the dry-cleaning industry, tetrachloroethylene (C(2)Cl(4)) can be a pollutant of residential indoor air, which can cause long-term harmful exposures because of its neurotoxicity and probable carcinogenicity. In France, dry-cleaning facilities are integrated in urban environments (shopping malls, residential buildings) and can contribute to C(2)Cl(4) exposure for customers and residents. This exploratory work presents the results from five studies carried out in one shopping mall and four residential buildings housing a dry-cleaning facility. These studies involved dry-cleaning machines fitted with a Carbon Adsorber and unfitted, with or without Air Exhaust System. Samples were collected in the cleaning facilities and in the apartments located above with passive samplers allowing measurement of time-integrated concentrations on a 7 days sampling period. It has obviously shown the degradation of indoor air quality in these environments and underlined the contributing role of the machine technology and ventilation system on the amount of released C(2)Cl(4) in the indoor air. To temper these results, it must be pointed out that some parameters (building insulation, amount of solvent used...) which would influence C(2)Cl(4) fugitive release have not been quantified and should be looked at in further studies. PRACTICAL IMPLICATIONS: In France, dry-cleaning facilities are frequently integrated in urban environments (large shopping malls or residential buildings) and can significantly contribute to tetrachloroethylene (C(2)Cl(4)) population exposure. The amount of fugitive releases in these environments depends on several parameters such as the dry-cleaning machine technology (fitted or unfitted with a carbon adsorber) and the ventilation (air exhaust system). To reduce C(2)Cl(4) exposure in residential buildings and other indoor environments with on-site dry cleaners, carbon adsorber unequipped machine should be replaced by newer technology and dry cleaners should be equipped with mechanical air exhaust systems.

Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments.

A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m3 Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91

Relaxin potentiates the expression of inducible nitric oxide synthase by endothelial cells from human umbilical vein in in vitro culture.

The hormone relaxin (RLX), which can be detected in human venous cord blood, has been shown to be a potent vasodilator, acting through increased expression of inducible nitric oxide synthase (NOS II) and nitric oxide (NO) generation. This study aims at clarifying whether RLX, at concentrations of 100 and 1000 ng/ml for 6 or 12 h of exposure, can influence the expression of NOS isoforms in human umbilical vein endothelial cells (HUVEC) cultured in vitro. NOS mRNA expression was studied by quantitative real-time RT-PCR, NOS protein expression and activity was studied by Western blot and nitrite assay, and immunoreactive NOS localization was performed by confocal microscopy. Untreated HUVEC expressed all the NOS isoforms, especially the constitutive, endothelial-type NOS III and, to a lesser extent, NOS II and NOS I. RLX-treated cells showed an increased expression of NOS II, attaining a maximum with 1000 ng/ml RLX, which gave rise to increased NO generation, as shown by nitrite assay. This effect of RLX appears to be mediated by activation of NOS II transcription factor NF-kappaB, since it was abolished by the NF-kappaB inhibitors curcumin-95 and dexamethasone. These findings suggest that RLX in the umbilical vein might contribute to the NO-dependent regulation of vascular tone.

Determination of urinary tryptophan and its metabolites along the nicotinic acid pathway by high performance liquid chromatography with ultraviolet detection.

A fast and sensitive method is given for analysing urinary tryptophan and six of its metabolites on the nicotinic acid pathway. Kynurenine, tryptophan, 3-hydroxykynurenine, anthranilic acid, 3-hydroxyanthranilic acid, kynurenic acid and xanthurenic acid were isocratically eluted and completely resolved with a mobile phase of acetonitrile + sodium acetate buffer, pH 4.76 (4:96, v/v). The flow rate was 0.8 mL/min at the beginning and was then linearly increased to 1.2 after 6 min; after 14 min the flow was augmented from 1.2 to 2 mL/min. The effluent was monitored with a variable UV detector set at 254 nm for the first five peaks and at 280 and 325 nm for the penultimate peak and final peak. Analytical recoveries of the compounds after deproteinization varied between 64% and 98%. The reported method should enable one to examine easily, extensively, quantitatively and routinely urinary tryptophan and the most important metabolites of the nicotinic acid pathway.

[Etiology of bladder cancer]. / Eziologia del carcinoma vescicale.

Multiple agents have been suggested as urinary bladder carcinogens. Of these, certain aromatic amines and some tryptophan metabolites (Anthranilic acid, 3 hydroxy Anthranilic acid) have been proved to be carcinogenic. Others are suggested but are not conclusively proved as carcinogenic agents. Various animal species have been used as experimental models for the study of induction of cancer of the bladder and substantial progress has been made in the search for etiologic factors and pathogenesis of bladder tumors. A carcinogenic model of cancer bladder induction is proposed. However, knowledge of the tumorigenesis of cancer of the bladder is still limited and fragmentary. It appears, however, that Tryptophan dysmetabolism play a major role in this field and future experimental and epidemiologic studies should take this fact into consideration.