Radmila Janković

Benign cystic mesothelioma of the peritoneum in a male child

The benign cystic mesothelioma of the peritoneum is a rare lesion that occurs predominatly in women of reproductive age and has a high propensity for local recurrence. It is very rare in childhood, especially in boys, being reported in only 4 cases. A new case of benign cystic mesothelioma of the peritoneum in an 11-year-old boy is reported. The lesion occupied the entire left abdomen, arising from the transverse mesocolon, and it was accompanied by 4 small cysts. The patient had a coexistent right-sided renal agenesis. The mesothelial nature of the cysts epithelial lining cells was confirmed by immunopositivity for calretinin, cytokeratin 5/6, HBME1, and epithelial membrane antigen (EMA). No recurrence of the lesion was noted in the 7-month follow-up. Pathologists and clinicians should be aware of the existence of this rare entity in childhood to establish an accurate diagnosis and provide close follow-up after the surgery.

Combined Contribution of Endothelial Relaxing Autacoides in the Rat Femoral Artery Response to CPCA: An Adenosine A2 Receptor Agonist

We examined the contribution of endothelial relaxing factors and potassium channels in actions of CPCA, potent adenosine A2 receptor agonist, on isolated intact male rat femoral artery (FA). CPCA produced concentration-dependent relaxation of FA, which was notably, but not completely, reduced after endothelial denudation. DPCPX, A1 receptor antagonist, had no significant effect, while SCH 58261 (A2A receptor antagonist) notably reduced CPCA-evoked effect. Pharmacological inhibition of nitric oxide synthase or cyclooxygenase comparably reduced CPCA-evoked action, still in a lesser degree than after denudation. In the presence of buffer with high K+ (100  mM), CPCA-produced relaxations were almost abolished. TEA (nonselective KCa blocker), glibenclamide (KATP blocker), Ba++ (KIR blocker), or ouabain (Na+/K+-ATPase inhibitor) did not change CPCA-induced relaxation. Concentration-response curve for CPCA was significantly shifted to the right after the incubation of apamin (SK channel blocker). CPCA produced concentration-dependent relaxation of FA that was partly dependent on endothelial cells. Endothelium-related portion of CPCA-elicited effect was mediated by combined action of endothelial NO, prostacyclin, and EDHF after activation of endothelial A2A receptors. Small conductance KCa channels were involved in this action.

Effects of diabetes and vascular occlusion on adenosine-induced relaxant response of rat common carotid artery

BACKGROUND The aim of this study was to investigate effect of adenosine on isolated rat common carotid artery (CA) submitted to occlusion in non-diabetic or diabetic animals, and to determine whether endothelium denudation or potassium conductance block affects adenosine action. METHODS Experiments were conducted on Wistar rat CA with or without endothelium. Diabetes was induced by alloxan. Occlusion of CA was performed in randomly selected non-diabetic or diabetic animals anesthetized with urethane. Thus, experiments were performed in four groups of rats: non-operated (control) animals without or with diabetes and operated animals submitted to the occlusion of CA without or with diabetes. Concentration-response curves for adenosine were obtained in a cumulative fashion on precontracted arteries. RESULTS Adenosine produced concentration-dependent and endothelium-independent relaxation of CA with comparable maximal effects in all groups. Analysis of pEC50 values showed that responsiveness of CA decreased in following order: [diabetes (-) / occlusion (-)] = [diabetes (-) / occlusion (+)] > [diabetes (+) / occlusion (-)] > [diabetes (+) / occlusion (+)]. In the presence of high K(+) maximal relaxant response of CA from non-operated rats without diabetes was reduced. The recorded inhibition was even stronger in animals subjected to CA occlusion. Conversely, in non-operated diabetic animals obtained reduction of adenosine effect was less pronounced in regard to non-diabetic rats. CONCLUSIONS Adenosine produced equi-effective endothelium-independent relaxation of CA in all groups. Pharmacological potency of adenosine was reduced in diabetic animals solely, but even more in diabetic rats submitted to CA occlusion. The enhanced potassium transmembrane flow has certain protective role on adenosine-induced action in occluded CA from non-diabetic rats. Conversely, diabetes solely inhibited adenosine-evoked cascade connected to increased potassium conductance.

Exploring the influence of CAPTCHA types to the users response time by statistical analysis

CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart. It is a test program that solves a given task for preventing the attacks made by automatic programs. If the response to CAPTCHA is correct, then the program classifies the user as a human. This paper introduces a new analysis of the impact of different CAPTCHAs to the Internet user’s response time. It overcomes the limitations of the previous approaches in the state-of-the-art. In this sense, different types of CAPTCHAs are presented and described. Furthermore, an experiment is conducted, which is based on two populations of Internet users for text and image-based CAPTCHA types, differentiated by demographic features, such as age, gender, education level and Internet experience. Each user is required to solve the different types of CAPTCHA, and the response time to solve the CAPTCHAs is registered. The obtained results are statistically processed by Mann-Whitney U and Pearson’s correlation coefficient tests. They analyze 7 different hypotheses which evaluate the response time in dependence of gender, age, education level and Internet experience, for the different CAPTCHA types. It represents an invaluable study in the literature to predict the best use of a given CAPTCHA for specific types of Internet users.

Comparative in vivo evaluation of novel formulations based on alginate and silver nanoparticles for wound treatments

In the present study, possibilities for using novel nanocomposites based on alginate and silver nanoparticles for wound treatment were investigated in a second-degree thermal burn model in Wistar rats. Silver nanoparticles (AgNPs) were electrochemically synthesized in alginate solutions that were further utilized to obtain the Ag/alginate solution and microfibers for subsequent in vivo studies. Daily applications of the Ag/alginate colloid solution, containing AgNPs, alginate and ascorbic acid (G3), wet Ag/alginate microfibers containing AgNPs (G5) and dry Ag/alginate microfibers containing AgNPs (G6) were compared to treatments with a commercial cream containing silver sulfadiazine (G2) and a commercial Ca-alginate wound dressing containing silver ions (G4), as well as to the untreated controls (G1). Results of the in vivo study have shown faster healing in treated wounds, which completely healed on day 19 (G4, G5 and G6) and 21 (G2 and G3) after the thermal injury, while the period for complete reepitelization of untreated wounds (G1) was 25 days. The macroscopic analysis has shown that scabs fell off between day 10 and 12 after the thermal injury induction in treated groups, whereas between day 15 and 16 in the control group. These macroscopic findings were supported by the results of histopathological analyses, which have shown enhanced granulation and reepithelization, reduced inflammation and improved organization of the extracellular matrix in treated groups without adverse effects. Among the treated groups, dressings based on Ca-alginate (G4-G6) induced enhanced healing as compared to the other two groups (G2, G3), which could be attributed to additional stimuli of released Ca2+. The obtained results indicated potentials of novel nanocomposites based on alginate and AgNPs for therapeutic applications in wound treatments.

Clarification of serotonin-induced effects in peripheral artery disease observed through the femoral artery response in models of diabetes and vascular occlusion: the role of calcium ions

Recent findings have demonstrated that serotonin is an important participant in the development and progression of peripheral artery diseases. Taking this into consideration, the goals of this study were to investigate the effects of serotonin on isolated Wistar rat femoral arteries in both healthy and diabetic animals, with and without artery occlusion, with a particular focus on determining the role of calcium in this process. Contraction experiments with serotonin on intact and denuded femoral artery rings, in the presence or absence of nifedipine and ouabain (both separately, or in combination), as well as Ca2+‐free Krebs‐Ringer bicarbonate solution were performed. The serotonin‐induced results were concentration dependent, but only in healthy animals. The endothelium‐dependent contraction of the femoral artery was assessed. In healthy animals, the endothelium‐reliant part of contraction was dependent on the extracellular calcium, while the smooth muscle‐related part was instead dependent on the intracellular calcium. In diabetic animals, both nifedipine and ouabain influenced serotonin‐induced vascular effects by blocking intracellular calcium pathways. However, this was diminished after the simultaneous administration of both blockers.

The analysis of transduction mechanisms associated with an acute action of homocysteine on isolated rat femoral artery

The present study was undertaken in order to examine transduction mechanism involved in the single application of 100 μM homocysteine (Hcy) on isolated rat femoral artery (RFA) rings equilibrated on the basal tone; to establish if a single application of 100 μM Hcy alters contractile effect of phenylephrine (Phe), or oppositely the relaxant effect of acetylcholine (ACh) or bradykinin (BK) after 60-min-long incubation of 100 μM Hcy; and finally to identify morphological changes on the vascular wall after a 24-h-long incubation of 100 μM Hcy. Hcy produced contractile response of intact RFA, which was increased after endothelial denudation, while decreased by urapidil (an α1 receptor blocker), nifedipine (a voltage-gated L-type Ca++ channel blocker) or indomethacin (a cyclooxygenase inhibitor). The initial RFA contraction evoked by Phe was further increased by the single addition of Hcy, which was not the case when ouabain (an inhibitor of Na+/K+-ATPase) was preincubated. After 60-min-long incubation of Hcy relaxant actions of ACh and BK were unaltered, equieffective and equipotent. A 24-h-long incubation of RFA rings with Hcy produced an impairment of vascular endothelium, expressed as a minor or more pronounced interruption of endothelial cells.

Exploring the Usability of the Dice CAPTCHA by Advanced Statistical Analysis

This paper introduces a new study of the Dice CAPTCHA usability based on advanced statistical analysis. An experiment is performed on a population of 197 Internet users, characterised by age and Internet experiences, to which the solution to the Dice CAPTCHA is required on a laptop or tablet computer. The response time, which is the solution time to successfully solve the CAPTCHA, together with the number of tries are registered for each user. Then, the collected data are subjected to association rule mining for analysing the dependence of the response time to solve the CAPTCHA in a given number of tries on the co-occurrence of the user’s features. This analysis is very useful to understand the co-occurrence of factors influencing the solution to the CAPTCHA, and accordingly, to realise which CAPTCHA is closer to the “ideal” CAPTCHA.

Analysis of the Reforming Languages by Image-Based Variations of LBP and NBP Operators

This paper proposes an extension of the local binary pattern and neighbor binary pattern as a basis for extracting features needed for recognizing an image which represents a text in specific languages. At the first, the unicode text is, according to its energy status in the text-line area, converted into a gray level image. Then, the extension of the local binary pattern and neighbor binary pattern is proposed. These features are extracted in order to differentiate image-based representations of a text in a given language. At the end, the extracted features are classified by Support Vector Machine and Naive Bayes to establish a difference that can identify different languages. The obtained results prove the accuracy and efficiency of the proposed method when compared with other state-of-the-art methods.

040: Myocardial bridging: comparative analysis of coronary angiography and autopsy results

Background Myocardial bridge (MB) is congenital myocardial band overriding a portion of a coronary artery, mainly LAD. Incidence on coronary angiography (CA) appears lesser than on autopsy, which can be ethnics-related, while clinically all forms of coronary artery disease (CAD) are reported: from benign arrhytmias up to sudden death. Aim We sought to determine incidence of MBs in the Serbian population along with respective clinical features. Methods Retrospective analysis was carried out in the same population, during the same 1-year time-frame and comprised consecutive: (A) 721 autopsies, with LM studies of the tunneled vessel (TV) wall together with the morphometric analysis of the ventricular myocardium supplied by TV (experimental group) and the ventricular myocardium of the same heart but with a different blood supply (control group); (B) 4510 CA of symptomatic patients were re-assessed for presence of MBs. Results (A) MBs were described in 6 cases (0.8%): 5 male, all over 70yrs. Only single MB over LAD were found, while all showed: a) TV’ intensive atherosclerotic changes proximal to MB, only focal in the tunneled part; b) intensive interstitial fibroses of the TV-supplied myocardium. (B) MBs were found in 42pts (0.93%): 33 male, aged of 55+11yrs, with single MB over the mid-LAD. 29% were CAD-free, 43% had 1-vessel CAD, 2-v-CAD (24%) and 3-v-CAD (4%). MBs were most frequent in hearts with right coronary dominance (69%). Hypertension and smoking were equally present (69%), dyslipidemia (59%), family history of CAD (48%) and diabetes (21%). Pts presented with stable angina (40%), nonspecific symptoms (14%), unstable angina (7%) and supraventricular arrhythmia (5%), with a history of an anterior wall STEMI vs. NSTEMI in 26% vs. 7%. Conclusions This first overview of MBs-incidence in Serbia (0.8% on autopsy vs. 0.9% on CA) might underestimate its actual presence, which prompted us to continue prospectively.