The microvascular network of the pituitary gland: a model for the application of fractal geometry to the analysis of angioarchitecture and angiogenesis of brain tumors.

In geometrical terms, tumor vascularity is an exemplary anatomical system that irregularly fills a three-dimensional Euclidean space. This physical characteristic, together with the highly variable vessel shapes and surfaces, leads to considerable spatial and temporal heterogeneity in the delivery of oxygen, nutrients and drugs, and the removal of metabolites. Although these biological features have now been well established, quantitative analyses of neovascularity in two-dimensional histological sections still fail to view tumor architecture in non-Euclidean terms, and this leads to errors in visually interpreting the same tumor, and discordant results from different laboratories.

Fractal analysis of two-dimensional vascularity in primary prostate cancer and surrounding non-tumoral parenchyma.

Prostate cancer is the fifth most frequent cancer in the world. However, none of the actual prognostic factors provide a valid index for predicting patient outcome. Here, we evaluate the two-dimensional vascularity in primary prostate tumors and surrounding non-tumoral parenchyma by means of fractal geometry, and assess any correlations between the results and some clinical and pathological parameters of prostate carcinoma.

Fractal dimension as a quantitator of the microvasculature of normal and adenomatous pituitary tissue.

It is well known that angiogenesis is a complex process that accompanies neoplastic growth, but pituitary tumours are less vascularized than normal pituitary glands. Several analytical methods aimed at quantifying the vascular system in two-dimensional histological sections have been proposed, with very discordant results. In this study we investigated the non-Euclidean geometrical complexity of the two-dimensional microvasculature of normal pituitary glands and pituitary adenomas by quantifying the surface fractal dimension that measures its space-filling property.

The complex functions of mast cells in chronic human liver diseases.

Mast cells (MCs) are multifunctional effector cells of the immune system. MCs were originally thought to be involved in IgE-associated immediate hypersensitivity and allergic disorders, but it is now known that they contain or elaborate an array of mediators with a multitude of effects on many other cells. A number of studies have found that MCs are involved in various liver diseases.

Early cytotoxic effects of ochratoxin A in rat liver: a morphological, biochemical and molecular study.

We characterized the overall early effect of chronic ochratoxin A (OTA) treatment on rat liver, analyzing different aspects related to: (i) fibrosis, by measuring collagen content and turnover, and alpha-smooth muscle actin (alphaSMA); (ii) oxidative stress and stress response, by analyzing protein carbonylation, superoxide dismutase (SOD) and heat shock protein (HSP70) gene expression; (iii) the possible tumor promoter effect, evaluating cadherin and connexin (CX) mRNA levels. Light microscopy analysis showed no histological differences in OTA-treated and control (CT) rats. Collagen content, determined by computer analysis of Sirius red-stained liver sections, was similar in both groups.