Chestnut ink disease, caused by Phytophthora cinnamomi and P. cambivora, is responsible for important economic losses and limits the establishment of new chestnut (Castanea sativa) groves in Portugal. Although the differences in soil properties and in cropping practices affect ink severity, the regional spread of disease is not known. Data for monitoring C. sativa decline were obtained by using field surveys and Small Format Aerial Photography (SFAP), a reliable tool which provides large-scale imagery obtained at low altitude. Visible colour and near-infrared images were obtained with different cameras with an average ground resolution of 22, 14 and 39 cm. The spatial distribution of ink disease in northern Portugal for the years 1995-2004 was estimated through a geostatistical method, and the estimation of precision was determined. From 1995-2002, the chestnut population in the study area increased by 18.5% due to new orchard plantations. After 2002 the population decreased because the new plantations were not sufficient to recover the number of dead chestnut trees, killed mostly by ink disease. The directional semivariograms indicated anisotropy with a greater disease spread in the NE-SW direction. This direction corresponds to site areas at the same altitude, where soil tillage and human mobility are higher.

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Putative cardiac progenitor cells (CPCs) have been identified in the myocardium and are regarded as promising candidates for cardiac cell-based therapies. Although two distinct populations of CPCs reached the clinical setting, more detailed studies are required to portray the optimal cell type and therapeutic setting to drive robust cell engraftment and cardiomyogenesis after injury. Owing to the scarcity of the CPCs and the need for reproducibility, the generation of faithful cellular models would facilitate this scrutiny. Here, we evaluate whether immortalized Lin(-)Sca-1(+) CPCs (iCPC(Sca-1)) represent their native-cell counterpart, thereby constituting a robust in vitro model system for standardized investigation in the cardiac field. iCPC(Sca-1) were established in vitro as plastic adherent cells endowed with robust self-renewal capacity while preserving a stable phenotype in long-term culture. iCPC(Sca-1) differentiated into cardiomyocytic-, endothelial-, and smooth muscle-like cells when subjected to appropriate stimuli. The cell line consistently displayed features of Lin(-)Sca-1(+) CPCs in vitro, as well as in vivo after intramyocardial delivery in the onset of myocardial infarction (MI). Transplanted iCPC(Sca-1) significantly attenuated the functional and anatomical alterations caused by MI while promoting neovascularization. iCPC(Sca-1) are further shown to engraft, establish functional connections, and differentiate in loco into cardiomyocyte- and vasculature-like cells. These data validate iCPC(Sca-1) as an in vitro model system for Lin(-)Sca-1(+) progenitors and for systematic dissection of mechanisms underlying CPC subsets engraftment/differentiation in vivo. Moreover, iCPC(Sca-1) can be regarded as a ready-to-use CPCs source for pre-clinical bioengineering studies toward the development of novel strategies for restoration of the damaged myocardium.

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SummaryChestnut ink disease caused by the oomycete Phytophthora cinnamomi, a soil-borne pathogen of world-wide distribution, accounts for the majority of disease problems on chestnuts in Portugal, limiting yield in a large number of stands and impeding establishment of trees in new areas. A survey was carried out in 32 chestnut stands in the Padrela Mountains of northern Portugal to investigate the relationship among ink disease occurrence, edaphic factors and management practices. A logistic regression function was employed to analyze the effect of soil attributes and management practices on the stand health status. Results showed that the main factors affecting disease were soil compaction (COMP), soil organic matter level (OM) and manuring practice (MA). A logistic model containing the soil variable COMP and the interaction term OM · MA correctly predicted the stand health status in 94%, or 30, of the 32 stands studied. The logistic function coefficients indicate that the probability of a stand having ink disease increases with increasing soil compaction and increasing soil organic matter content in stands where manuring is the usual practice.