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The biological reactivity of ambient air particles was studied in five in vitro lung macrophage assays, involving the release of cytoplasmic and lysosomal enzymes, cellular ATP, neutral red uptake, tetrazolium reduction, and chemiluminescence. Macrophages from rat lungs (2 x 10(5) cells; 1 cm(2) attachment surface; 1 ml culture medium) were exposed for 18(More)
The membranolytic and cytotoxic properties of two naturally occurring (chrysotile asbestos; attapulgite clay) and two man-made (Fiberfrax, an aluminium-silicate, and xonotlite, a calcium silicate) industrial minerals were compared. "Short" fiber fractions of chrysotile and Fiberfrax were obtained by sedimentation in demineralized water, while the(More)
Coelomocytes were extruded from three earthworm species: Lumbricus terrestris, Eisenia fetida and Octolasion tyrtaeum. Featuring a simple low-vacuum holding device, the proposed methodology allows the recovery of cells with minimum risk of contamination by faecal material. The viability of O. tyrtaeum coelomocytes was highly reproducible (average 93%), with(More)
Aramid fibres have been proposed as a substitute for many asbestos uses. Although dimensional characteristics of aramid fibres vary with the type of application, some of the commercial grades proposed contain fibres whose geometry is clearly in a range where biological reactivities have been reported for other natural or man-made fibres. We wish to report(More)
A recombinant form of hirudin (HIR), a potent thrombin inhibitor derived from the leech Hirudo medicinalis, was cloned and expressed in the methylotrophic yeast Pichia pastoris. The HIR gene was inserted into the P. pastoris pPic9K expression vector such that the gene's expression is under alcohol oxidase (AOX1) promoter control and the HIR coding sequence(More)
The addition of 1 part of 1.5 M NaCl or 2.5 M sucrose (10 X concentrate) to 9 parts of Percoll produces a stock solution that is hypertonic (350-360 mOsm/kg H2O). Because the osmolality is a critical variable in the isopycnic separation of cells and cell organelles, the factors accountable for this hypertonicity were investigated. Percoll, a colloidal(More)
The inflammatory and fibrogenic potential of three naturally occurring and two man-made industrial minerals were compared. Groups of five rats each received respectively a single intratracheal instillation of saline (control), UICC chrysotile B asbestos, short chrysotile 4T30, attapulgite, xonotlite (a calcium silicate), and Fiberfrax (an aluminum silicate)(More)
In order to study the cellular and biochemical changes in early asbestosis, three groups of sheep were repeatedly exposed to intratracheal instillations of either saline (controls), low doses of UICC chrysotile asbestos (LD), or high doses of the fibers (HD) until an alveolitis was observed in all HD sheep during the twelfth month of exposure. All sheep(More)
The poly(ADP-ribose) polymerase (PARP-1), a 113 kDa nuclear enzyme, is cleaved in fragments of 89 and 24 kDa during apoptosis. This cleavage has become a useful hallmark of apoptosis and has been shown to be done by DEVD-ase caspases, a family of proteases activated during apoptosis. Interestingly, PARP-1 is also processed during necrosis but a major(More)
Induction of heat shock proteins (Hsps) is often associated with a cellular response to a harmful stress or to adverse life conditions. The main aims of the present study were (1) to assess if stress-induced Hsp70 could be used to monitor exposure of the earthworm species Lumbricus terrestris to various soil pollutants, (2) to assess the specificity of(More)