Photocatalytic degradation of methylene blue under natural sunlight using iron titanate nanoparticles prepared by a modified sol-gel method.

The aim of this work was to synthesize semiconducting oxide nanoparticles using a simple method with low production cost to be applied in natural sunlight for photocatalytic degradation of pollutants in waste water. Iron titanate (Fe2TiO5) nanoparticles with an orthorhombic structure were successfully synthesized using a modified sol-gel method and calcination at 750°C. The as-prepared Fe2TiO5 nanoparticles exhibited a moderate specific surface area. The mesoporous Fe2TiO5 nanoparticles possessed strong absorption in the visible-light region and the band gap was estimated to be around 2.16 eV. The photocatalytic activity was evaluated by the degradation of methylene blue under natural sunlight. The effect of parameters such as the amount of catalyst, initial concentration of the dye and pH of the dye solution on the removal efficiency of methylene blue was investigated. Fe2TiO5 showed high degradation efficiency in a strong alkaline medium that can be the result of the facilitated formation of OH radicals due to an increased concentration of hydroxyl ions.

Burkholderia cepacia complex in Serbian patients with cystic fibrosis: prevalence and molecular epidemiology.

The Burkholderia cepacia complex (Bcc) organisms remain significant pathogens in patients with cystic fibrosis (CF). This study was performed to evaluate the prevalence, epidemiological characteristics, and presence of molecular markers associated with virulence and transmissibility of the Bcc strains in the National CF Centre in Belgrade, Serbia. The Bcc isolates collected during the four-year study period (2010-2013) were further examined by 16 s rRNA gene, pulsed-field gel electrophoresis of genomic DNA, multilocus sequence typing analysis, and phylogenetic analysis based on concatenated sequence of seven alleles. Fifty out of 184 patients (27.2 %) were colonized with two Bcc species, B. cenocepacia (n = 49) and B. stabilis (n = 1). Thirty-four patients (18.5 %) had chronic colonization. Typing methods revealed a high level of similarity among Bcc isolates, indicating a person-to-person transmission or acquisition from a common source. New sequence types (STs) were identified, and none of the STs with an international distribution were found. One centre-specific ST, B. cenocepacia ST856, was highly dominant and shared by 48/50 (96 %) patients colonized by Bcc. This clone was characterized by PCR positivity for both the B. cepacia epidemic strain marker and cable pilin, and showed close genetic relatedness to the epidemic strain CZ1 (ST32). These results indicate that the impact of Bcc on airway colonization in the Serbian CF population is high and virtually exclusively limited to a single clone of B. cenocepacia. The presence of a highly transmissible clone and probable patient-to-patient spread was observed.

Long-term prognostic significance of living alone and other risk factors in patients with acute myocardial infarction.

BACKGROUND: Living alone has been associated with higher risk of acute coronary syndrome in general population, but there are no consistent findings about its effect on prognosis after acute myocardial infarction (AMI). AIM: To analyse the relationships between living alone and other risk factors at baseline and long-term survival after AMI. METHODS: One hundred and thirty-five patients with confirmed myocardial infarction (MI) admitted to the coronary care unit of the Institute of Cardiovascular Diseases, Clinical Centre of Serbia in Belgrade, between June 2002 and April 2006, were followed up until September 2011. Survival time was estimated using the Kaplan-Meier method and Cox regression analysis. RESULTS: Patients with MI were followed up for a median of 77 months. The mean age of participants was 57.82 years (SD ± 10.8), and one quarter of them were women. According to the multivariate Cox regression analysis stratified on marital status, the model in which were included living alone, age, gender, education, obesity, smoking, hyperlipidaemia, hypertension, diabetes mellitus, previous cardiovascular and other disease, thrombolytic therapy and localisation of MI, the following variables were found to be independent predictors of death after AMI: living alone, with a hazard ratio (HR) of 7.60 [95 % confidence interval (CI) 1.99-29.08], diabetes mellitus (HR 3.31; 95 % CI 1.33-8.23), current smoking (HR 2.82; 95 % CI 1.03-7.71) and, older age (HR 1.13; 95 % CI 1.06-1.19). CONCLUSION: The results of this study support hypothesis that patients who live alone have higher long-term all-cause mortality following AMI.

Trends in macrolide resistance of respiratory tract pathogens in the paediatric population in Serbia from 2004 to 2009.

We report the first study of macrolide resistance in respiratory tract pathogens in a Serbian paediatric population. It included 5293 Streptococcus pneumoniae, 4297 Streptococcus pyogenes, 2568 Moraxella catarrhalis and 1998 Haemophilus influenzae isolates derived from the respiratory tract and 110 invasive isolates from children aged up to 18 years during 2004-2009. Over the 6-year period, a significant increase (P < 0·01) in macrolide resistance was found in both S. pneumoniae and S. pyogenes that reached 45% and 19%, respectively, in 2009. In the same period, consumption of macrolides increased continually from 2·46 to 5·8 defined daily dose/1000 inhabitants per day. The increase in macrolide resistance in S. pyogenes correlated with consumption of total macrolide and long-acting macrolides (r = 0·879, P = 0·05 and r = 0·922, P = 0·026, respectively). A similar trend was observed in pneumoccoci, although it did not reach statistical significance. The growing problem of macrolide resistance in pneumococci and S. pyogenes in Serbia requires further vigilant surveillance.

Ventricular and vascular remodelling effects of the angiotensin II receptor blocker telmisartan and/or the angiotensin-converting enzyme inhibitor ramipril in hypertensive patients.

Angiotensin II induces inflammatory activation of vascular smooth muscle cells and can cause left ventricular hypertrophy (LVH). Telmisartan is an angiotensin II receptor blocker with demonstrated beneficial effects on cardiac and vascular structure and function in animal models. The angiotensin-converting enzyme inhibitor ramipril also reduces ventricular and vascular remodelling. The open-label study observed 75 treatment-naive, moderately or severely hypertensive (systolic blood pressure 160-190 mmHg, diastolic blood pressure 90-110 mmHg) patients (age range, 42-58 years) treated with once-daily telmisartan 40 mg force-titrated to 80 mg after 1 month (n=25), once-daily ramipril 2.5 mg force-titrated to 5 mg after 1 month (n=25), or once-daily telmisartan 40 mg plus ramipril 2.5 mg (n=25); the total duration of treatment was 6 months. At baseline, blood pressure, left ventricular mass index (LVMI), carotid intima-media thickness (IMT) and carotid cross-sectional intima-media area (CSA) were measured. Measurements were repeated 1, 3 and 6 months after initiation of treatment. After 6 months, comparable blood pressure reductions were achieved with the three treatments. Reductions in LVMI after 6 months' treatment were 11.4%, 9.9% and 15.6% with telmisartan, ramipril, and telmisartan plus ramipril, respectively. Respective reductions in IMT were 14.6%, 12.0% and 18.2%, and for CSA were 7.8%, 4.3% and 11.5%. In conclusion, treatment with telmisartan or ramipril for 6 months resulted in regression of LVH and vascular remodelling. When a combination of telmisartan and ramipril was administered, additional regression and remodelling occurred.

The importance of antioxidant enzyme and total antioxidant status of patients with acute myocardial infarction on thrombolytic therapy.

It is believed that intensive production of free radicals occurs immediately after reperfusion, and that it explains a series of adverse effects of reperfusion. The aim of the study was to establish the importance of the antioxidative enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX) and the total antioxidant status (TAS) in patients with acute myocardial infarction according to success or failure of reperfusion. Enzyme activities in erythrocyte hemolysate and concentration of TAS in plasma were determined by Randox kits in 50 patients with acute myocardial infarction. No significant differences in TAS between the mean values against either clinical status or the 10 time intervals were recorded. The SOD and GPX values were significantly influenced by the presence or absence of reperfusion (p<0.05). Monitoring of SOD and GPX at ten time points: before administration of streptokinase, 1, 3, 6, 12, 18, 24 hours, 2, 3 and 5 days after administration of streptokinase revealed the lowest SOD levels up to one hour before administration of streptokinase, supporting the fact that the maximum production of free radicals is achieved at that time. GPX values differed for 24 hours according to whether reperfusion was achieved or not. The obtained results suggest that free radical production is increased after reperfusion, and monitoring of antioxidant enzymes may help to evaluate the success of thrombolytic therapy.

The involvement of immune reactions in cardiac damage during acute myocardial infarction: role of cell-mediated immune response.

This study was undertaken with the aim of investigating humoral and cell-mediated immune response in acute myocardial infarction (AMI) as possible mechanisms involved in the infarction enlargement. Twenty three patients with first AMI and 15 healthy volunteers were examined. Of the AMI patients, 14 had extensive infarction (group A), while 9 patients had small infarction (group B). Immunologic analyses were performed at admission, and repeated after 3, 7, 14 and 21 days of the acute event. Following parameters were tested: number of CD3+, CD4+, CD8+ and CD20+ cells; serum IgG, IgA, IgM, C3, C4, immune complex and anticardiac antibody levels; polymorphonuclear cell (PMN) function (chemotaxis, phagocytosis, metabolic activity); leukocyte migration in vitro in the presence of water-soluble homologous heart extract. It was demonstrated that the number of B cells, serum IgG, C3, immune complex and anticardiac antibody levels were elevated from 7th-14th days after AMI. Concerning these parameters, however, no significant differences were obtained between group A and group B of AMI patients. Chemotaxis and metabolic activity of peripheral blood PMN, but not phagocytosis, were enhanced during AMI, again changes of PMN did not correlate with the extension of infarction. In contrast, leukocyte migration inhibition in vitro revealed that only patients with extensive AMI have developed positive reaction during the first 14 days after the onset of the disease, while leukocyte inhibition reaction appeared in patients with nonextensive AMI not earlier than the 21st day after the infarction. These findings demonstrate generation of immune reactivity during AMI and indicate that humoral immune response seems more likely to be an epiphenomenon related to tissue necrosis, while cell-mediated immune reactions could influence the extensiveness of cardiac damage.

Common form of Lyme borreliosis carditis--complete heart block with syncope: report on 3 cases.

Third degree atrioventricular (AV) heart block with severe Adams-Stokes attacks in 3 patients with Lyme borreliosis is described. All patients had similar clinical manifestations: previously healthy, they experience syncope as an abrupt onset of the disease. Data on skin changes--erythema migrans--was subsequently obtained, although the patients did not recall being bitten by a tick. Diagnoses were based on clinical manifestations and on positive serologic test results to borrelia. Following AV block returned to sinus rhythm with normal AV conduction in all patients.

[Epidemiology of Lyme borreliosis]. / Epidemiologija Lyme borreliosis.

Our prospective study covered 1093 patients with epidemiological features and demonstrable clinical manifestations of Lyme borreliosis from 1987 to 1992. Basic criteria for the inclusion of our patients in the study were: tick bite, erythema migrans and antibodies to B. burgdorferi in each patient's serum. Various clinical manifestations were found un 1034 (94.6%) patients out of whom 829 (80.2%) had a history of tick bite, 901 (87.1%) had erythema migrans and 217 (21.0%) had serologic confirmation of the diagnosis. Inapparent infection was discovered in 59 (5.4%) patients. Other Types of skin changes (II and III stage) were found in 123 (11.9%) patients. The disease resulted in neurologic, joint and cardiac manifestations in somewhat lower percentage of patients (6.3%, 6.6% and 1.5%, respectively). In the three-year period (1990-1992) microscopic examination of the ticks (Ixodes ricinus) collected at several green areas of Belgrade confirmed the presence of B. burgdorferi in 29.1 per cent.

[Clinical picture of cardioborreliosis: from AV block to perimyocarditis]. / Klinicki oblici kardioborelioze: od A-V bloka do perimiokarditisa.

The third degree A-V heart block with severe Adams-Stokes attacks in nine patients with Lyme borreliosis was described. All patients had similar clinical picture: previously healthy with syncope as abrupt onset of the disease. Data on skin changes--erythema migrans--were obtained subsequently although the patients did not recall being bitten by a tick. Diagnosis was based on clinical manifestation, and on positive serologic tests to Borrelia. After the administered therapy (on admission atropine 0.5 mg i.v., and/or isoproterenol 0.02 mcg/kg/min, temporary pace-maker in two patients; and after proved diagnosis penicillin 20 mil. unit per day 10 days, and tetracyclin 2.0 gr per day 20 days A-V block returned to sinus rhythm with normal A-V conduction, and all biochemical parameters returned to normal limits. Perimyocarditis is not rare during Lyme borreliosis, but in this case infection syndrome is dominant.

[The role of echocardiography in the evaluation of cardiac damage in Lyme disease]. / Uloga ehokardiografije u proceni ostecenja srca u lajmskoj bolesti.

Lyme disease is an infectious, multisystem disease involving the skin, heart, joints, and nervous system. With its ability to assess cardiac anatomy, chamber sizes and myocardial and valvular function, echocardiography is a powerful noninvasive tool to investigate possible cardiac involvement in this disorder. We studied by echocardiography 15 patients, (6 women and 9 men, mean age 28.5 years, range 17 to 42) with clinical and electrocardiographic changes compatible with acute myocarditis or myopericarditis. 14 patients (pts) had transitory complete heart block and one patient had ventricular extrasystolic arhythmia. A first patient group (n = 6) who had a tick bite (Lyme antibody titers were found in three patents) was compared with a group (n = 9) without such confirmation. In first group two pts had small pericardial effusion and two pts had a nonspecific, discrete and small myocardial fibrosis after 3-6 months echocardiographic follow-up. Chambers sizes and indexes of left ventricular systolic and diastolic function were normal. Similar findings were found in the other group. We concluded that echocardiographic findings is not specific for Lyme disease, but echocardiography is an excellent tool for assessing the presence and degree of cardiac dysfunction and therefore provides essential information for the management of these patients.

[Comparative effects of dihydropyridine inhibitors of calcium penetration on spontaneous contraction of the isolated heart atria in the guinea pig]. / Effets comparatifs des inhibiteurs dihydropyridiques de la pénétration calcique sur les battements spontanés des oreillettes isolées du Cobaye.

All DHPs (nifedipine, nicardipine, nitrendipine) produced a concentration-dependent depression of the isometric contraction and of the atrial rate of the isolated, spontaneously beating atria of the guinea-pig. The depressive actions of nifedipine and nitrendipine were completely antagonized by the addition of calcium, aminophylline and isoprenaline. Aminophylline partially, calcium almost completely and isoprenaline completely antagonized the depressive action of nicardipine on the isometric contraction. Only isoprenaline antagonized the effect of DHPs on the atrial rate of the isolated, spontaneously beating atria of the guinea-pig. It is possible that all these substances restore the contractibility of the atria by compensating the calcium balance, previously changed by DHPs, or by producing an increase in the intracellular cyclic AMP content (aminophylline and isoprenaline).

Morphological changes of erythrocytes in patients and carriers of Duchenne disease.

The morphology of erythrocytes was investigated in 7 patients with Duchenne dystrophy and in 6 carriers of the same disease. Upon immediate fixation, the erythrocytes showed significant stomatocytosis which was observed in a scanning electron microscope. The mean value of the % of stomatocytes was significantly different in carriers compared to healthy people (P less than 0.01).