Treatment with hAFS cells has a reparative potential through active involvement of cells in alveolarization and angiogenesis. A downstream paracrine action was also taken into account, in order to understand the immunodulatory response.

In the last few years some studies have shown the possibility of deriving progenitors with various potential from the amniotic fluid. Amniocentesis is a widely accepted method for prenatal diagnosis; it is associated with low risk both for the mother and the fetus and overcomes the ethical problems commonly associated to other sources. Recently we have described that amniotic fluid stem (AFS) cells, for their ability to differentiate to various lineages, could represent a good candidate for therapeutic applications. For gene therapy purposes human AFS (hAFS) cells should be genetically modified with a therapeutic gene and delivered systematically or injected directly into the tissue of interest. The aim of this study was to investigate the feasibility of transducing hAFS cells with adenoviral vectors and to determine whether transduced stem cells retain the ability to differentiate into different lineages. Herein, we showed that hAFS cells could be efficiently infected by first generation adenovirus vectors. In addition, we demonstrated that infection and expression of two different marker genes, LacZ and EGFP, have no effect on cells phenotype and differentiation potential. In particular, on undifferentiated status, hAFS cells continued to express both the transgenes and stemness cell markers OCT4 and SSEA4. When cultured under mesenchymal conditions, infected cells could still differentiate into osteocytes and adipocytes expressing lineage specific genes. These preliminary findings suggest that adenovirus may be useful to engineer populations of pluripotent stem cells, which may be used in a wide range of gene therapy treatments.

We conclude that administering L: -citrulline proved effective in improving alveolar and vascular growth in a model of oxygen-induced pulmonary damage, suggesting better lung growth and matrix regulation than in untreated groups.

No abstract

Premature newborns may be exposed to hyperoxia in the first postnatal period, but clinical and experimental works have raised the question of oxygen toxicity for the developing brain. However, specific analysis of hyperoxia exposure on neurogenesis is still lacking. Thus, the aim of the present study was to evaluate possible changes in the morphometric parameters of the main neurogenic sites in newborn rats exposed to 60 or 95 % oxygen for the first 14 postnatal days. The optical disector, a morphometric method based upon unbiased sampling principles of stereology, was applied to analyse cell densities, total volumes, and total cell numbers of the dentate gyrus (DG) and subventricular zone (SVZ). Apoptosis and proliferation were also studied by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling method and anti-ki67 immunohistochemistry, respectively. Severe hyperoxia increased the percentage of apoptotic cells in the DG. Moderate and severe hyperoxia induced a proliferative response both in the DG and SVZ, but the two neurogenic sites showed different changes in their morphometric parameters. The DG of both the hyperoxic groups showed lower volume and total cell number than that of the normoxic one. Conversely, the SVZ of newborn rats exposed to 95 % hyperoxia showed statistically significant higher volume and total cell number than SVZ of rats raised in normoxia. Our findings indicate that hyperoxia exposure in the first postnatal period affects both the neurogenic areas, although in different ways, i.e. reduction of DG and expansion of SVZ.

No papers are available about potentiality of fractal analysis in quantitative assessment of alveolarization in bronchopulmonary dysplasia (BPD). Thus, we here performed a comparative analysis between fractal [fractal dimension (D) and lacunarity] and stereological [mean linear intercept (Lm), total volume of alveolar air spaces, total number of alveoli, mean alveolar volume, total volume and surface area of alveolar septa, and mean alveolar septal thickness] parameters in experimental hyperoxia-induced models of BPD. At birth, rats were distributed between the following groups: 1) rats raised in ambient air for 2 wk; 2) rats exposed to 60% oxygen for 2 wk; 3) rats raised in normoxia for 6 wk; and 4) rats exposed to 60% hyperoxia for 2 wk and to room air for further 4 wk. Normoxic 6-wk rats showed increased D and decreased lacunarity with respect to normoxic 2-wk rats, together with changes in all stereological parameters except for mean alveolar volume. Hyperoxia-exposed 2-wk rats showed significant changes only in total number of alveoli, mean alveolar volume, and lacunarity with respect to equal-in-age normoxic rats. In the comparison between 6-wk rats, the hyperoxia-exposed group showed decreased D and increased lacunarity, together with changes in all stereological parameters except for septal thickness. Analysis of receiver operating characteristic curves showed a comparable discriminatory power of D, lacunarity, and total number of alveoli; Lm and mean alveolar volume were less discriminative. D and lacunarity did not show significant changes when different segmentation thresholds were applied, suggesting that the fractal approach may be fit to automatic image analysis.

No abstract

L-Cit improved alveolar and vascular growth diminishing the lung inflammatory response in the newborn rats exposed to intra-amniotic LPS. The ADMA/DDAH/NO pathway appeared to counteract proinflammatory cytokine production and to sustain macrophage migration.