Extravasation of leukocytes in comparison to tumor cells

The multi-step process of the emigration of cells from the blood stream through the vascular endothelium into the tissue has been termed extravasation. The extravasation of leukocytes is fairly well characterized down to the molecular level, and has been reviewed in several aspects. Comparatively little is known about the extravasation of tumor cells, which is part of the hematogenic metastasis formation. Although the steps of the process are basically the same in leukocytes and tumor cells, i.e. rolling, adhesion, transmigration (diapedesis), the molecules that are involved are different. A further important difference is that leukocyte interaction with the endothelium changes the endothelial integrity only temporarily, whereas tumor cell interaction leads to an irreversible damage of the endothelial architecture. Moreover, tumor cells utilize leukocytes for their extravasation as linkers to the endothelium. Thus, metastasis formation is indirectly susceptible to localization signals that are literally specific for the immune system. We herein compare the extravasation of leukocytes and tumor cells with regard to the involved receptors and the localization signals that direct the cells to certain organs and sites of the body

Evaluation of prediction capability of the MaxEnt and Frequency Ratio methods for landslide susceptibility in the Vernazza catchment (Cinque Terre, Italy)

none6The research is focused on the Vernazza catchment, an area of 5,75 km2 belonging to the Vernazza municipality in the Cinque Terre National Park, Italy; here, landslide susceptibility maps are produced using two different statistical methods by analyzing several intrinsic factors controlling landslides. It is also intended to evaluate the maps to determine the comparison between the coverage of high susceptibility areas obtained through different methods. The first statistically based method is a presence–absence (Frequency Ratio) method, while the second one is a presence-only (MaxEnt) method; the acquisition and preparation of the predisposition factors are also described, as well as their sensitivity and hierarchy regarding the landslide susceptibility models. Furthermore, in order to understand the effective improvement brought by the performance of the models, a validation using the receiving operator characteristics (ROC) and the area under curve (AUC) techniques has been carried out. The role played by variables such as land use and FAS is well visible: the outputs generated through both methods show a uniform distribution of very high susceptibility values on the medium-lower right portion of the catchment, and also the “aspect” variable, in which the value of each cell in a dataset indicates the direction of the cell’s slope faces, strongly influences the results since the west–south west-facing cells are considered as prone to generate landslides. Results obtained for assessing landslide susceptibility show good prediction rate curves for both the tested methodologies, with higher values for the frequency ratio susceptibility model. However, for the MaxEnt susceptibility models, these values are lower, though, without ever decreasing below 0.60. In both cases, future developments of the adopted methods could involve a further distinction of landslide type to evaluate the potential of model prediction specifically for each landslide category.mixedRaso, Emanuele; Di Martire, Diego; Cevasco, Andrea; Calcaterra, Domenico; Scarpellini, Patrizio; Firpo, MarcoRaso, Emanuele; Di Martire, Diego; Cevasco, Andrea; Calcaterra, Domenico; Scarpellini, Patrizio; Firpo, Marc

Genetics of Moyamoya disease

Moyamoya disease (MMD) is a disease pattern consisting of bilateral stenosis of the intracranial internal carotid arteries (ICA) accompanied by a network of abnormal collateral vessels that bypass the stenosis. Once symptomatic, insufficient cerebral blood flow or rupture of the fragile collaterals may cause stroke or hemorrhage, resulting in severe neurological dysfunction or death. The etiology of MMD is still unknown, although few associations with other diseases and environmental factors have been described. Strong regional differences in epidemiological data, as well as known familial cases, turned the focus to genetics for the insight into the disease's pathogenesis. Thus far, several reports have suggested specific genetic loci and individual genes as predisposing to MMD, but none have demonstrated reproducible results in independent cohorts. Small sample sizes, as well as a likely multifactorial origin, seem to be the most challenging tasks in identifying the disease-causing mechanisms. Once identified, susceptibility genes may allow preventive screening and a possible development of novel therapeutic options