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Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants, and many are potent carcinogens. Benzo[a]pyrene (B[a]P), one of the best-studied PAHs, is metabolized ultimately to the genotoxin anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE triggers stress responses linked to gene expression, cell death and survival. So far, the underlying mechanisms that initiate these signal transduction cascades are unknown. Here we show that BPDE-induced DNA damage is recognized by DNA damage sensor proteins to induce activation of the stress-activated protein kinase (SAPK) p38. Surprisingly, the classical DNA damage response, which involves the kinases ATM and ATR, is not involved in p38-SAPK activation by BPDE. Moreover, the induction of p38-SAPK phosphorylation also occurs in the absence of DNA strand breaks. Instead, increased phosphorylation of p38-SAPK requires the nucleotide excision repair (NER) and DNA damage sensor proteins XPC and mHR23B. Interestingly, other genotoxins such as cisplatin (CDDP), hydrogen peroxide and ultraviolet radiation also enhance XPC-dependent p38-SAPK phosphorylation. In contrast, anti-benzo[c]phenanthrene-3,4-dihydrodiol-1,2-epoxide, the DNA adducts of which are not properly recognized by NER, does not trigger p38-SAPK activation. As a downstream consequence, expression and secretion of the pro-inflammatory cytokine interleukin-6 is induced by BPDE and CDDP in vitroand by CDDP in the murine lung, and depends on XPC. In conclusion, we describe a novel pathway in which DNA damage recognition by NER proteins specifically leads to activation of p38-SAPK to promote inflammatory gene expression.

AbstractSome nuclear facilities have large tritium loads and subsequent environmental emissions and consequently, the radiological impact assessment is mandatory. In case of the unplanned (potential) accidents there are extremely large uncertainties of the model predictions for crop contamination and dose due to many factors affecting the Organically Bound Tritium (OBT) dynamics in crops. A full mechanistic model is difficult to develop due to the complexity of the processes involved in tritium transfer and the environmental conditions. The preparatory steps for a robust model are discussed in the present study, considering the role of the dry matter and photosynthesis contributing to the OBT dynamics in crops.

This paper describes the experimental work performed at the Research Centre Karlsruhe and insights gained into the processes relevant for modelling of the tritium behaviour in plants. It presents results of the model application to short term exposure of tritium and highlights the possible reasons for deviations from the observations.

Fly ash was used as a model for ambient particulate matter which is under suspicion to cause adverse pulmonary health effects. The fly ash was pre-sized and contained only particles < 20 μm including an ultrafine fraction (< 100 nm) that contributed 31% to the particle number. In our study, we investigated the influence of fly ash on the promotion of early inflammatory reactions like the formation of reactive oxygen species (ROS) in rat lung epithelial cells (RLE-6TN). Furthermore, we determined the formation of nitric oxide (NO). The cells show a clear dose-response relationship concerning the formation of ROS with regard to the mass of particles applied. Lipopolysaccharide (LPS) added as a co-stimulus did not increase the formation of ROS induced by fly ash. Furthermore, in LPS (01 μg/ml) and tumour necrosis factor-alpha (TNF-alpha; 1 ng/ml) pre-treated cells no increase in reactive oxygen species comparable to fly ash alone is observable. In presence of the metal chelator, desferrioxamine (DFO), ROS formation can be significantly reduced. Neither fly ash nor LPS induced a significant NO release in RLE-6TN cells.

Summary The precursor glycoproteins HN0 and F0 in the surface spikes of Newcastle Disease Virus strain Ulster as produced by MDBK cells, were found to contain 10.4 and 11.9 weight per cent, respectively, of the sugars typical forN-glycosidically linked glycoprotein glycans. A molar ratio ofD-mannose:D-galactose:L-fucose:N-acetyl-D-glucosamine approaching 1.0:1.1:0.5:1.0 was found for HN0, and of 1.0:0.7:0.3:0.6 for F0.

La tuberculose (TB) est un motif fréquent d’hospitalisation dans les pays développement malgré le traitement en ambulatoire. Le but notre travail était d’étudier le motif d’hospitalisation des patients tuberculeux sous chimiothérapie antituberculeuse dans un service de pneumophtisiologie.

Les maladies allergiques sont en constante progression dans le monde mais peu d’études ont été consacrées aux allergies respiratoires en Afrique subsaharienne. Le but de notre travail était de déterminer le profil de sensibilisation au Prick-test des pneumallergènes chez des patients asthmatiques et ou rhinitiques présumés allergiques.

No abstract.