Risk Evaluation of Pollutants Emission from Coal and Coal Waste Combustion Plants and Environmental Impact of Fly Ash Landfilling.

Emission factors (EFs) of gaseous pollutants, particulate matter, certain harmful trace elements, and polycyclic aromatic hydrocarbons (PAHs) from three thermal power plants (TPPs) and semi-industrial fluidized bed boiler (FBB) were compared. EFs of particulate matter, trace elements (except Cd and Pb), benzo[a]pyrene, and benzo[b]fluoranthene exceed the upper limits specified in the EMEP inventory guidebook for all combustion facilities. The comparison of trace elements and PAHs content in fly ashes (FAs) from lignite and coal waste combustion in TPPs and FBB, respectively, as well as the potential environmental impact of FAs disposal, was performed by employing a set of ecological indicators such as crustal enrichment factor, risk assessment code, risk indices for trace elements, and benzo[a]pyrene equivalent concentration for PAHs. Sequential analysis shows that the trace elements portion is the lowest for water-soluble and exchangeable fractions. The highest enrichment levels in FAs are noticed for As and Hg. Based on toxic trace elements content, FAs from TPPs represent a very high ecological risk, whereas fly ash from FBB poses a moderate ecological risk but has the highest benzo[a]pyrene equivalent concentration, indicating its increased carcinogenic potential. Lead isotope ratios for Serbian coals and FAs can contribute to a lead pollution global database.

Distribution of PAHs in coal ashes from the thermal power plant and fluidized bed combustion system; estimation of environmental risk of ash disposal.

The comparison of fly ash generated from lignite combustion in a thermal power plant Kolubara A (Veliki Crljeni) and bottom and fly ash from coal waste combustion in a semi-industrial fluidized bed boiler (Vinca) was performed as the function of particle size. The average total concentrations of the 16 EPA priority PAHs in ash fractions are 0.49 mg kg-1 of ash (thermal power plant) and 17.48 mg kg-1 of ash (fluidized bed boiler). The sum of 3- and 4-ring PAHs accounts for more than 93% of overall PAHs concentration, and the most abundant among them is fluoranthene. The portions of PAHs groups defined based on their physico-chemical properties, as obtained from quantitative structure-activity relationship (QSAR) models included in the Vega platform, were determined. These portions, emission factors, and benzo[a]pyrene equivalence concentrations were further on used to estimate the potential environmental impact of ash disposal. The PAHs emission factors are higher compared to values in the air pollutant emission inventory guidebook of the cooperative program for monitoring and evaluation of the long-range transmission of air pollutants in Europe (EMEP/EEA). The overall emission factors of 16 PAHs for combustion of lignite and coal waste are determined to be 0.15 and 249.97 mg kg-1 of fuel, respectively. Based on the ratios of benzo[a]pyrene equivalence concentrations of each ash and correspondent fuel, the disposal of fly ash from the cyclone of fluidized bed boiler represents the highest risk to the environment among tested ashes.

Yellow gentian root extract provokes concentration- and time-dependent response in peripheral blood mononuclear cells.

Yellow gentian (Gentiana lutea L.), a medicinal plant widely used in traditional medicine, displays multiple biological effects, ranging from beneficial to toxic. Since many promising applications have been reported so far, our aim was to evaluate its potential concentration- and time- dependent cytotoxic and genotoxic effects in vitro. To that end we exposed human peripheral blood mononuclear cells to 0.5, 1, and 2 mg/mL of yellow gentian root extract (YGRE) to determine its effects on oxidative stress parameters [pro/antioxidant balance (PAB) and lipid peroxidation], DNA damage (alkaline comet assay and chromosome aberrations), and cell viability (trypan blue exclusion test). Cell viability decreased with increasing concentrations and treatment duration. Only the lowest YGRE concentration (0.5 mg/mL) increased oxidative stress but produced minor DNA damage and cytotoxicity. At higher concentrations, redox parameters returned to near control values. The percentage of chromosome aberrations and percentage of DNA in the comet tail increased with increased YGRE concentration after 48 h and declined after 72 h of treatment. This points to the activation of DNA repair mechanism (homologous recombination), evidenced by the formation of chromosomal radial figures after 72 h of treatment with the highest YGRE concentration of 2 mg/mL. Our results suggest that YGRE, despite induction of cytotoxic and genotoxic effects, activates cell repair mechanisms that counter oxidative and DNA lesions and induce cell death in highly damaged cells. Therefore, observed protective effects of yellow gentian after longer exposure could be a result of activated repair and removal of cells with irreparable damage.

Comparison of fine particulate matter level, chemical content and oxidative potential derived from two dissimilar urban environments.

Urban airborne particles contain a wide spectrum of components, known to have harmful effects on human health. This study reports a detailed investigation of fine particulate matter (PM2.5), chemical content and oxidative potential derived from two different urban environments. During summer and winter, 20-day campaigns were conducted at Belgrade city center (urban-background site - UB) and Bor (urban-industrial site - UI). Using various analytical techniques, carbonaceous compounds, water-soluble inorganic ions, major and trace elements were determined, while the oxidative potential of PM2.5 was estimated by dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay (OPDCFH values). The mean PM2.5 concentrations in both urban environments were above the recommended daily value, and the dominant PM2.5 mass contributor was organic matter (29-55%). The OC/EC ratio was significantly higher at UB site during winter, which was an indication of a considerable contribution of secondary organic carbon to the overall organic carbon (OC). Water-soluble organic carbon (WSOC) was also higher at UB than at UI site, and it probably came from the same sources as OC. In general, the different partition of secondary organic aerosol (SOA) in warm and cold periods affected the number of organic components. Sulfates and nitrates were the most abundant ions at both sites and they counted approximately 40% (summer) and 50% (winter) of total ions. Further, the concentrations of the most elements, particularly some potentially carcinogenic elements such as As, Cd and Pb were significantly higher at UI, due to the emissions from the copper smelter complex in the vicinity. The mean OPDCFH values were similar during the summer at both sampling sites, whereas a statistically significant difference between sites was noticed in favor of UB environment in winter.

Measurements of Oxidative Potential of Particulate Matter at Belgrade Tunnel; Comparison of BPEAnit, DTT and DCFH Assays.

To estimate the oxidative potential (OP) of particulate matter (PM), two commonly used cell-free, molecular probes were applied: dithiothreitol (DTT) and dichloro-dihydro-fluorescein diacetate (DCFH-DA), and their performance was compared with 9,10-bis (phenylethynyl) anthracene-nitroxide (BPEAnit). To the best of our knowledge, this is the first study in which the performance of the DTT and DCFH has been compared with the BPEAnit probe. The average concentrations of PM, organic carbon (OC) and elemental carbon (EC) for fine (PM2.5) and coarse (PM10) particles were determined. The results were 44.8 ± 13.7, 9.8 ± 5.1 and 9.3 ± 4.8 µg·m-3 for PM2.5 and 75.5 ± 25.1, 16.3 ± 8.7 and 11.8 ± 5.3 µg·m-3 for PM10, respectively, for PM, OC and EC. The water-soluble organic carbon (WSOC) fraction accounted for 42 ± 14% and 28 ± 9% of organic carbon in PM2.5 and PM10, respectively. The average volume normalized OP values for the three assays depended on both the sampling periods and the PM fractions. The OPBPEAnit had its peak at 2 p.m.; in the afternoon, it was three times higher compared to the morning and late afternoon values. The DCFH and BPEAnit results were correlated (r = 0.64), while there was no good agreement between the BPEAnit and the DTT (r = 0.14). The total organic content of PM does not necessarily represent oxidative capacity and it shows varying correlation with the OP. With respect to the two PM fractions studied, the OP was mostly associated with smaller particles.

UV-C light irradiation enhances toxic effects of chlorpyrifos and its formulations.

UV-C irradiation is widely used in the food industry. However, the health effects from dietary exposure to the irradiated pesticide residues retained in foodstuffs are underestimated. In this study, technical chlorpyrifos (TCPF) and its oil in water (EW) and emulsifiable concentrate (EC) formulations were irradiated by UV-C, and their photodegradation products were subjected to toxicity assessment, including determination of acetylcholinesterase (AChE) activity, genotoxicity and oxidative stress using human blood cells as a model system. Toxicity studies were performed using the chlorpyrifos concentrations in the range of those proposed as the maximum residue levels in plant commodities. TCPF, EW and EC photodegradation products induced DNA damage and oxidative stress, and their genotoxicity did not decrease as a function of irradiation time. Irradiated TCPF and EC are more potent AChE inhibitors than irradiated EW. Accordingly, the application of UV-C irradiation must be considered when processing the plants previously treated with chlorpyrifos formulations.

Statistical modeling for Bayesian extrapolation of adult clinical trial information in pediatric drug evaluation.

Children represent a large underserved population of "therapeutic orphans," as an estimated 80% of children are treated off-label. However, pediatric drug development often faces substantial challenges, including economic, logistical, technical, and ethical barriers, among others. Among many efforts trying to remove these barriers, increased recent attention has been paid to extrapolation; that is, the leveraging of available data from adults or older age groups to draw conclusions for the pediatric population. The Bayesian statistical paradigm is natural in this setting, as it permits the combining (or "borrowing") of information across disparate sources, such as the adult and pediatric data. In this paper, authored by the pediatric subteam of the Drug Information Association Bayesian Scientific Working Group and Adaptive Design Working Group, we develop, illustrate, and provide suggestions on Bayesian statistical methods that could be used to design improved pediatric development programs that use all available information in the most efficient manner. A variety of relevant Bayesian approaches are described, several of which are illustrated through 2 case studies: extrapolating adult efficacy data to expand the labeling for Remicade to include pediatric ulcerative colitis and extrapolating adult exposure-response information for antiepileptic drugs to pediatrics.

Brain Injury Alters Ectonucleotidase Activities and Adenine Nucleotide Levels in Rat Serum.

BACKGROUND: Cortical stab injury (CSI) induces changes in the activity, expression and cellular distribution of specific ectonucleotidases at the injury site. Also, several experimentally induced neuropathologies are associated with changes in soluble ectonucleotidase activities in the plasma and serum, whilst various insults to the brain alter purine compounds levels in cerebrospinal fluid, but also in serum, indicating that insults to the brain may induce alterations in nucleotides release and rate of their hydrolysis in the vascular system. Since adenine nucleotides and adenosine regulate diverse cellular functions in the vascular system, including vascular tone, platelet aggregation and inflammatory responses of lymphocytes and macrophages, alterations of ectonucleotidase activities in the vascular system may be relevant for the clinical outcome of the primary insult. METHODS: We explored ectonucleotidase activities using specific enzyme assays and determined adenine nucleotides concentrations by the UPLC method in the rat serum after cortical stab injury. RESULTS: At 4-h post-injury, ATP and AMP hydrolysis increased by about 60% and 40%, respectively, while phosphodiesterase activity remained unchanged. Also, at 4-h post-injury a marked decrease in ATP concentration and more than 2-fold increase in AMP concentration were recorded. CONCLUSIONS: CSI induces rapid up-regulation of nucleotide catabolizing soluble ectonucleotidases in rat serum, which leads to the observed shift in serum nucleotide levels. The results obtained imply that ectonucleotidases and adenine nucleotides participate in the communication between the brain and the vascular system in physiological and pathological conditions and thereby may be involved in the development of various human neuropathologies.

Inhibition of Na(+)/K(+)-ATPase and cytotoxicity of a few selected gold(III) complexes.

Na(+)/K(+)-ATPase is in charge of maintaining the ionic and osmotic intracellular balance by using ATP as an energy source to drive excess Na(+) ions out of the cell in exchange for K(+) ions. We explored whether three representative cytotoxic gold(III) compounds might interfere with Na(+)/K(+)-ATPase and cause its inhibition at pharmacologically relevant concentrations. The tested complexes were [Au(bipy)(OH)2][PF6] (bipy=2,2'-bipyridine), [Au(py(dmb)-H)(CH3COO)2] (py(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-pyridine), and [Au(bipy(dmb)-H)(OH)][PF6] (bipy(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-2,2'-bipyridine). We found that all of them caused a pronounced and similar inhibition of Na(+)/K(+)-ATPase activity. Inhibition was found to be non-competitive and reversible. Remarkably, treatment with cysteine resulted in reversal or prevention of Na(+)/K(+)-ATPase inhibition. It is very likely that the described effects may contribute to the overall cytotoxic profile of these gold complexes.

Biochemical characterization of soluble nucleotide pyrophosphatase/phosphodiesterase activity in rat serum.

Biochemical properties of nucleotide pyrophosphatase/phosphodiesterase (NPP) in rat serum have been described by assessing its nucleotide phosphodiesterase activity, using p-nitrophenyl-5'-thymidine monophosphate (p-Nph-5'-TMP) as a substrate. It was demonstrated that NPP activity shares some typical characteristics described for other soluble NPP, such as divalent cation dependence, strong alkaline pH optimum (pH 10.5), inhibition by glycosaminoglycans, and K (m) for p-Nph-5'-TMP hydrolysis of 61.8 +/- 5.2 microM. In order to characterize the relation between phosphodiesterase and pyrophosphatase activities of NPP, we have analyzed the effects of different natural nucleotides and nucleotide analogs. ATP, ADP, and AMP competitively inhibited p-Nph-5'-TMP hydrolysis with K (i) values ranging 13-43 microM. Nucleotide analogs, alpha,beta-metATP, BzATP, 2-MeSATP, and dialATP behaved as competitive inhibitors, whereas alpha,beta-metADP induced mixed inhibition, with K (i) ranging from 2 to 20 microM. Chromatographic analysis revealed that alpha,beta-metATP, BzATP, and 2-MeSATP were catalytically degraded in the serum, whereas dialATP and alpha,beta-metADP resisted hydrolysis, implying that the former act as substrates and the latter as true competitive inhibitors of serum NPP activity. Since NPP activity is involved in generation, breakdown, and recycling of extracellular adenine nucleotides in the vascular compartment, the results suggest that both hydrolyzable and non-hydrolyzable nucleotide analogs could alter the amplitude and direction of ATP actions and could have potential therapeutic application.

Toxic effects of diazinon and its photodegradation products.

The toxic effects of diazinon and its irradiated solutions were investigated using cultivated human blood cells (lymphocytes and erythrocytes) and skin fibroblasts. Ultra Performance Liquid Chromatography (UPLC)-UV/VIS system was used to monitor the disappearance of starting diazinon during 115-min photodegradation and formation of its by-products (diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol (IMP)) as a function of time. Dose-dependent AChE and Na(+)/K(+)-ATPase inhibition by diazinon was obtained for all investigated cells. Calculated IC(50) (72 h) values, in M, were: 7.5x10(-6)/3.4x10(-5), 8.7x10(-5)/6.6x10(-5), and 3.0x10(-5)/4.6x10(-5) for fibroblast, erythrocyte and lymphocyte AChE/Na(+)/K(+)-ATPase, respectively. Results obtained for reference commercially purified target enzymes indicate similar sensitivity of AChE towards diazinon (IC(50) (20 min)-7.8x10(-5)M), while diazinon concentrations below 10mM did not noticeably affect Na(+)/K(+)-ATPase activity. Besides, diazinon and IMP induced increasing incidence of micronuclei (via clastogenic mode of action) in a dose-dependent manner up to 2x10(-6)M and significant inhibition of cell proliferation and increased level of malondialdehyde at all investigated concentrations. Although after 15-min diazinon irradiation formed products do not affect purified commercial enzymes activities, inhibitory effect of irradiated solutions on cell enzymes increased as a function of time exposure to UV light and resulted in significant reduction of AChE (up to 28-45%) and Na(+)/K(+)-ATPase (up to 35-40%) at the end of irradiation period. Moreover, photodegradation treatment strengthened prooxidative properties of diazinon as well as its potency to induce cytogenetic damage.

Application of flavonoids - quercetin and rutin - as new matrices for matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of Pt(II) and Pd(II) complexes.

Attempts are being made to overcome the resistance of tumour cells to platinum (Pt) drugs by the synthesis of new generations of Pt complexes, and it is important to find appropriate and simple methods for the characterization of those novel complexes. The additional applicability of such a method for the analysis of the interactions of metal complexes with biomolecules would be advantageous. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) seems to possess the capability to become this method of choice, since it could be applied to low-mass complexes as well as for the analysis of large biomolecules. In this work the applicability of flavonoids - quercetin and rutin - as matrices for MALDI-TOFMS analysis of dichlorido(ethylendiamine)platinum(II) ([PtCl(2)(en)]), dichlorido(diaminocyclohexane)platinum(II) ([PtCl(2)(dach)]) and chloride (diethylenetriamine) palladium(II) chloride ([PdCl(dien)]Cl) complexes is demonstrated. Spectra of Pt(II) and Pd(II) complexes recorded in the presence of quercetin and rutin are rather simple: Pt(II) complexes generate [M+Na](+) or [M+K](+)ions, whereas the investigated Pd(II) complex gives ions generated by the loss of one Cl(-) or HCl. Flavonoids give a relatively small number of well-defined ions in the low-mass region (at m/z 303.3 for quercetin and m/z 633.5 for rutin). Quercetin and rutin can be applied in much lower concentrations than other common MALDI matrices and require rather low laser intensity. We speculate that flavonoids stabilize the structures of the metal complexes and that they may be useful for the analysis of other biologically active metal complexes, thus implying their broader applicability.

Interaction of the [PtCl2(DMSO)2] complex with L-cysteine.

The reaction between [PtCl2(DMSO)2] and L-cysteine (L-Cys) has been investigated in the presence of micelles of sodium dodecyl sulfate (SDS)--as a model for biological membranes. Additionally, the inhibitory effect of [PtCl2(DMSO)2] on the Na+,K+-ATPase activity and its partial prevention with 10 mM L-Cys were demonstrated. The interaction of L-Cys with [PtCl2(DMSO)2] resulted in the formation of a [Pt(DMSO)2(L-Cys)2]2+ (DMSO)2] complex, which most probably occurs through stepwise replacement of Cl(-) with L-Cys. It has also been demonstrated that neither the pH value nor SDS affects the composition of the new complex. On the other hand, the pH value and SDS do affect the reaction rate, most probably due to electrostatic interactions with reactants. In summary, this study can be used as a simple model approach for the investigation of reaction mechanisms between platinum complexes and various biomolecules, and for the determination of potential toxicity and/or side effects of antitumour platinum drugs.

Fabrication, in vitro degradation and the release behaviours of poly(DL-lactide-co-glycolide) nanospheres containing ascorbic acid.

Ascorbic acid (vitamin C) is essential for preserving optimal health and is used by the body for many purposes. The problem is that ascorbic acid easily decomposes into biologically inactive compounds making its use very limited in the field of pharmaceuticals, dermatological and cosmetics. By encapsulating the ascorbic acid into a polymer matrix it is assumed that its chemical instability can be overcome as well as higher, more efficient and equally distributed concentration throughout extended period of time can be achieved. This paper is describing the process of obtaining poly(dl-lactide-co-glycolide) (DLPLG) nanospheres (110-170 nm) using chemical method with solvent/non-solvent systems where obtained solutions have been centrifuged. The encapsulation of the ascorbic acid in the polymer matrix is performed by homogenisation of water and organic phases. Nanoparticles of the copolymer DLPLG with the different contents of the ascorbic acid have different morphological characteristics, i.e. variable degree of uniformity, agglomeration, sizes and spherical shaping. The degradation of the nanospheres of DLPLG, DLPLG/ascorbic acid nanoparticles and release rate of the ascorbic acid were studied for 8 weeks in a physiological solution (0.9% sodium chloride in water). The samples have been characterised by infrared spectroscopy (IR), scanning electron microscopy (SEM), stereological analysis and ultraviolet (UV) spectroscopy.