TY  - JOUR
AB  - Particularly since the wide-ranging health effects of asbestos exposure became known, great emphasis has been placed on detailed toxicity testing of known but also newly developed fiber materials. Exposure to respirable pollutants like fibers can lead to tissue injury causing lung diseases such as pulmonary fibrosis or cancer. In order to detect the toxic potential of such aerosols at an early stage, the development of suitable test systems is essential. In this study, we illustrate the development of an advanced in vitro cell model closely resembling the physiological structure of the alveoli, and we highlight its advantages over simpler models to predict pro-fibrotic changes. For this reason, we analyzed the cytotoxic effects of fiber-like multi-walled carbon nanotubes after 24 and 48 h exposure, and we investigated inflammatory, genotoxic and pro-fibrotic changes occurring in the developed triple culture consisting of lung epithelial cells, macrophages and fibroblasts compared to a co-culture of epithelial cells and fibroblasts or a mono culture of epithelial cells. In summary, the triple culture system is more precisely able to detect a pro-fibrotic phenotype including epithelial-mesenchymal transition as well as secondary genotoxicity, even if exhibiting lower cytotoxicity in contrast to the less advanced systems. These effects might be traced back to the complex interplay between the different cell types, all of which play an important role in the inflammatory response, which precedes wound healing, or even fibrosis or cancer development.
AU  - Pantzke, J.
AU  - Offer, S.
AU  - Zimmermann, E.
AU  - Kuhn, E.
AU  - Streibel, T.
AU  - Oeder, S.
AU  - Di Bucchianico, S.
AU  - Zimmermann, R.
C1  - 66983
C2  - 53395
TI  - An alternative in vitro model considering cell-cell interactions in fiber-induced pulmonary fibrosis.
JO  - Toxicol. Mech. Methods
PY  - 2022
SN  - 1091-7667
ER  - 

TY  - JOUR
AU  - Halbach, St.
AU  - Welzl, G.
C1  - 4956
C2  - 21975
SP  - 293-299
TI  - In-situ measurements of low-level mercury vapor exposure from dental amalgam with zeeman atomic absorption spectroscopy.
JO  - Toxicol. Mech. Methods
VL  - 14
PY  - 2004
SN  - 1091-7667
ER  - 

TY  - JOUR
AB  - Investigation of the toxicokinetics of mercury upon inhalation of the vapor (Hg° requires an exposure system characterized by rapid development and stability of preselected Hg° concentrations, continuous operation over variable exposure times, easy monitoring of Hg° concentration in air, and ready determination of Hg in organs and carcasses. This can be realized by generating Hg° from the reduction of Hg2+ labeled with radioactive 203Hg2+. Since the commonly used reducing agents stannous chloride (SnCl2) or sodium borohydride (NaBH4) gave unsatisfactory results, the reducing properties of hypophosporous acid (HPH2O2) were tested. Continuous measurement with atomic absorption spectrometry (AAS) showed that rise time of Hg° concentration was below 10 min and that the plateau was stable and higher than with the other reductants. The concentration of Hg° in air was linearly correlated to that of Hg2+ in solution. Concentrations of 203Hg in the wasted solution were below 5% of that of the initial Hg2+ solution, i.e., vaporization of Hg was nearly complete. The time to attain 90% of the steady-state Hg° concentration in the exposure chamber can be calculated to be 3.7 min, which is in accordance with 4.6 min actually measured. Body burden and organ distribution of Hg were determined after exposure to 0.5, 1.0, and 2.0 mg Hg°m3 for 1, 2, and 3 h. Under these conditions Hg uptake was linearly correlated to exposure time or concentration.
AU  - Halbach, S.
AU  - Fichtner, R.
C1  - 32672
C2  - 35213
SP  - 25-36
TI  - Generation of radioactive mercury vapor and its application in an exposure system.
JO  - Toxicol. Mech. Methods
VL  - 3
IS  - 1
PY  - 1993
SN  - 1091-7667
ER  -