Spatial-temporal analysis and risk characterisation of pesticides in Alpine glacial streams.

We analysed the spatial and temporal distribution of a selection of pesticides in Alpine glaciers used on the Po Plain in Northern Italy, near the Alps. By analysing a 102-m ice core taken from the Lys Glacier (Monte Rosa massif, Italy), we highlight historical contamination from the insecticide chlorpyrifos and the herbicide terbuthylazine, confirming the role of alpine glaciers as temporal sinks. In addition, we collected meltwater samples from six glaciers distributed along the Alpine Arc during the summer of 2016, which showed widespread contamination by pesticides. Overall, chlorpyrifos and terbuthylazine dominated the contaminant fingerprint of all of the studied glaciers, with contamination peaks occurring at the beginning of the melting season. This highlights the importance of the medium-range atmospheric transport of these pesticides in connection with agricultural practices in the areas beneath the Italian Alps, where they are widely applied. The release of pesticides in meltwater can lead to potential risks to the aquatic ecosystems of headwater streams, as we demonstrate for chlorpyrifos. This suggests that the medium-range atmospheric transport of pesticides should be considered as part of regulations to protect the water quality of these pristine environments.

Extracellular matrix and radiation G1 cell cycle arrest in human fibroblasts.

It is thought that sublethal doses of radiation cause cells to pause in either G1 or G2 phase, but that then cells with repaired DNA damage reenter the cell cycle. However, it has been observed that gamma-irradiation causes normal human fibroblasts to arrest indefinitely in G1 phase unless the irradiated cells are subcultured. This indicates that cell adhesion plays a role in maintaining the arrest. We now show that the type of extracellular matrix dramatically affects the percentage of cells that arrest in G1 phase. The prolonged radiation G1 arrest in human fibroblasts has been referred to as "senescence-like"; however, we find that smooth muscle alpha-actin is highly expressed in cells that arrest in G1 phase after irradiation. This indicates that the fibroblasts differentiate to myofibroblasts. Together, our results show that the length of radiation G1 arrest in human fibroblasts is affected by the type of extracellular matrix on which the cells are irradiated and that arrest results in myofibroblast differentiation.

Observations on an unusual enzyme distribution pattern in the colon of a case of familial polyposis with malignant changes.

Acid and alkaline phosphatases, esterases, and beta-glucuronidase were studied histochemically in the colon of a patient with familial polyposis in whom malignant changes had occurred. The acid hydrolases were found to be localized mainly in the supranuclear region of the cells of the epithelium of the normal mucosa. In the polyp epithelium these enzymes were found mainly in the basal areas of the epithelium at the junction between the latter and the lamina propria. In the cancer cells enzyme activity was decreased and distributed randomly. Alkaline phosphatase was present only in the capillaries in the normal and the polypmucosa. In the cancer tissue this enzyme was found in the capillaries, the smooth muscle cells, and the invading cells of epithelial origin.