The aim of this paper is to examine aggressive behaviors among Romanian high school students between 15 and 16 years old, to compare data in two national representative samples and to identify factors associated with physical fighting. This study investigates the association of selected factors (social, school performance and substance use) with physical fighting. A total of 2289 Romanian students were included in the 2007 database and 2770 in the 2011 database. This study revealed that 35.87% of the teenagers have taken part in a physical fight during the previous 12 months, as compared with the European average of 31.5%. Romania has the highest prevalence of violent behavior by participating in a group bruising of an individual in both surveys, 2007 and 2011. A logistic regression analysis performed for the 2011 study revealed the following factors associated with physical fighting: binge drinking during the previous 30 days, male gender, serious problems with friends, parent(s) who do not know where and with whom the adolescents spend their evenings, poor parental caring, low school grades, and high truancy. A decrease in almost all aggressive behaviors was noticed in 2011, compared to 2007. These findings may be useful to support and guide policy makers regarding improvement and implementation of strategies to further prevent aggressive behaviors in teenagers.

Arterial endothelium produces a large ramge of active factors which are indispensable for modulation of vasomotor tone and maintenance of vascular wall integrity. From these factors, nitric oxide (NO), wich is released by the endothelial cells as a response to acetylcholine or adenosine action on specific receptors, plays an important role.NO is the result of oxidation process of L-arginine into L-citrulline, under the action of endothelial nitric oxide synthase (NOSe), wich is activated by intracelluar Ca2+ - calmodulin complex . Our study, performed in isolated organ bath, analyzed vascular reactivity of 12 guinea pigs� thoracic aorta rings. After phenylephrine -PHE 10-5 mol/L precontraction, the dose-effect curves for acetylcoline � ACH, adenosine 5� phosphate - 5�ADP and sodium nitroprusside � SNP were determined, before and after incubation of preparation, for 1 hour, with 5% hydrosoluble cigarettes smoke extract (CSE). Statistic analysis, performed with the use of t pair test and ANOVA parametric test, showed that incubation of vascular preparation with 5% CSE has increased the contractile response to PHE 10-5 mol/L (p[0.05), has reduced the endothelium-dependent relaxing response to ATP 10-5 mol/L (p[0.001) and 5�ADP 10-5 molo/L (p[0.001), but has not significantly modified the endothelium-independent relaxing response to SNP 10-5 mol/L (p=0.05). As a conclusion, vascular rings incubation with 5% CSE induced a decrease of endothelium NO synthesis under the action of AXH and 5�ADP, but did not change the smooth muscle fiber respomse in the presence of NO released by SNP.

It can be observed that oxidative stress initiates and aggravates many diseases, including peptic ulcers and gastric carcinoma. An increase in rat mucosal glandular lipid peroxidation (LPO) and superoxide dismutase (SOD) and a decrease in catalase (CAT) levels in gastric ulceration induced by cold retention stress were observed, whereas in patients with ulcerated clinical peptic and gastric carcinoma LPO serum is associated with a decrease in SOD and CAT. It was intended to determine the parameters of oxidative stress in the blood and brain in rats after induction of gastric ulcer, the effect of antioxidant treatment on these parameters and on the appearance of gastric ulcer, determination of correlation between oxidative stress and severity of gastric ulcer in rats and also evaluation of vascular endothelial function by in vitro studies in the organ bath, from rat aortic rings with gastric ulcer vs. normal and others under treatment vs. untreated.

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Although oxidative stress itself is directly associated with the occurrence of atherosclerosis, and together with endothelial dysfunction is a marker of atherosclerotic risk, none of these two markers were directly correlated with the presence of atherosclerosis. This study investigated the correlation between oxidative stress and endothelial dysfunction in people with cardiovascular disease. Furthermore, another objective of this paper is the direct study of the effect of a compound with antioxidant properties, selenium, on a model of endothelial dysfunction induced on human vascular fragments.