Morphometric study of aortic wall parameters evolution in newborn and child.

The largest artery in the human body, intimately connected to the heart, aorta is usually regarded as the major source of oxygenated blood for the circulatory system. The three concentric layers, which surround the aortic lumen-the tunics intima, media and adventitia, transform the aorta in a large elastic duct, which is irregular calibrated according to its segments. The special aortic distensibility is facilitated by its elastic circumferential lamellar complex. Any disturbance of its structural components is able to interfere with its normal and vital activity. Our study intends to reveal that the development of elastic lamellae should be regarded not only as an indispensable step for the aortic wall configuration, but also like a process in a firm connection with the rest of aortic wall components. The transition from intrauterine life to a new stage of life, childhood, has to determine an adequate adaptation of almost all the components of aortic wall, in order to sustain a consistent pulsatile blood flow. Stereological quantitative analysis of thoracic aortic fragments prelevated from newborns and children was performed in order to estimate the dynamic of vascular wall increase. We first estimated the general configuration of the thoracic aortic wall, quantifying the principal constituents; the connective tissue profile, investigated through its main elements, collagen and elastic fibers, supports the idea that each type of fiber has a distinct evolution in different groups of ages and has to be correlated with their involvement in maintaining of the aortic wall mechanical properties. Elastic fibers percentage volume was increased in both examined groups, with a small difference reported in children aorta, while collagen fibers exhibit a slow increase in children aorta. Our morphometric quantitative assessment suggests that further studies have to draw of in a precisely manner the outline of the secretory well defined function of vascular smooth muscle cells; the elucidation of the manner in which the secretory pathway for each type of fiber becomes fully adapted to every stage of aortic development will allow a new perspective in aortic pathology.

The relevance of circadian rhythms disruption on pulmonary SOD expression in rat.

The light-dark cycle represents a significant component of the circadian system in most mammals. Any disturbance of this cycle is reflected in a large number of changes in the physiological and also behavioral status of the organism, together with considerable alterations of the redox balance. Increasing evidence suggests that reactive oxygen species (ROS) have their own function in the circadian system. Superoxide dismutases (SOD) family represents the first prompt antioxidant enzymatic system, identified in all aerobic organisms and able to counteract ROS toxicity; there are three distinct isoenzymes: CuZn-SOD (SOD1), Mn-SOD (SOD2), and extracellular EC-SOD (SOD3). In the case of circadian disruption, when ROS production is enhanced, the impact of the oxidative aggression on superoxide dismutases (SOD) rhythmicity and distribution is still unclear. To estimate the influence of circadian rhythms disruption on pulmonary SOD, we exposed male Wistar rats to continuous light stimuli for four weeks and then investigated the SOD immunohistochemical expression in lungs, which are among the most sensitive organs to oxygen. CuZn-SOD, Mn-SOD and EC-SOD presented a particular immunoreactivity in the investigated pulmonary tissues. These findings support our viewpoint that there is a direct correlation between the rhythmicity of circadian cycles and pulmonary SOD expression.

Adipokines involvement in lung function.

The last two decades brings many data about white adipose tissue capacity to secrete hormones, named adipokines, which could mediate the relationship between obesity and lung diseases. In this paper we presented some data about adipokines involvement on pulmonary function, with special emphasis on leptin, adiponectin, tumor necrosis factor alpha, vascular endothelial growth factor, resistin, hepatocyte growth factor, interleukin-6, angiotensinogen and apelin.