Exposure to submicron particles (PM1.0) from diesel exhaust and pollen allergens of human lung epithelial cells induces morphological changes of mitochondria tonifilaments and rough endoplasmic reticulum.

In recent literature, little has been said regarding the morphological changes that occur in lung cells after treatment with particles and nanoparticles. Using an in vitro model of type-II lung epithelium (A549), we studied the effects of submicron particles (PM1.0), Parietaria officinalis (ALL), and PM1.0 + ALL together. To date several biochemical effects have been described, instead few data exist in literature regarding morphological events following these treatments, in particular we focused on the morphological changes and distribution of mitochondria, tonifilaments and rough endoplasmic reticulum, using a transmission electron microscopic (TEM) approach. After exposure to PM1.0 particles (PM1.0), Parietaria officinalis as allergen, and PM1.0 with P. officinalis, changes in the cytoplasmic area were observed, such as damage to mitochondria and morphological alterations of the tonifilaments and rough endoplasmic reticulum. The data obtained strongly support the hypothesis that cells in contact with submicron particles (PM1.0), or P. officinalis, undergo alteration of their metabolism.

Differentiation of human umbilical cord-derived mesenchymal stem cells, WJ-MSCs, into chondrogenic cells in the presence of pulsed electromagnetic fields.

During cartilage regeneration, proliferation and differentiation of new chondrocytes are required and towards this goal, in humans electromagnetic stimulation has been used in order to increase the spontaneous regenerative capacity of bone and cartilage tissue. In vivo tissue engineering has pointed out that the absence of an abundant source of cells accelerating the healing process is a limiting factor in the ability to repair articular cartilage. Considering that the umbilical cord is a viable alternative source of mesenchymal stem cells (MSC), our study evaluated the possibility of a combined use of Wharton's jelly - mesenchymal stem cells (WJ-MSCs) and pulsed electromagnetic field (PMEF). The first effect observed was that compared with the untreated cells, when the WJ-MSCs were treated with PMEF, there was an increase in the division of cells and a rapid increase in cell density and the morphological and biochemical data showed that the treatment with PMEF reduced the time to obtain chondrocyte cell differentiation and deposition of extracellular matrix. Taken together these data indicate the capacity of PEMF to induce early differentiation of WJ-MSCs cells towards cartilaginous tissue.

Cardiovascular prosthetic surgery: an analysis of cellular and molecular patterns underlying valve implantation failure.

Cardiac valves have a very complex microscopic architecture, this is due to the presence of many cell types and to the variegated stroma. From a morphological point of view, both physiological and pathological processes clearly show there to be an anatomic continuity between valve leaflets and perivalvular tissues; indeed, both component should be taken into consideration during thrombotic processes and in fibrous tissue formation. At present, morphological features are well known and classified, while little is known about histogenetic features: fibrous tissue formation and the role of the various types of adhesion molecules and cells which participate in this process still have to be fully elucidated. In the current study, we focused on the histological analysis of the pannus. In particular, we demonstrated that the true connective nature of the exuberant fibrous tissue was entirely composed of collagen/fibronectin fibre bundles and fibroblasts. Moreover we observed that the phlogistic infiltrates were composed of immune cells, mainly represented by CD4(+) and CD8(+) T lymphocytes. Finally we also tried to assess not only the degree of endothelial layer loss, but also the extent of revascularization in the exuberant fibrous tissue.