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The objective of this work was to evaluate antioxidant defence and oxidative damage in organs (liver, gills, kidney, and brain) of five fish species (Aspius aspius, Esox lucius, Sander lucioperca, Abramis brama, Rutilus rutilus) from the long-term mercury-contaminated Skalka Reservoir in the Czech Republic. Special emphasis was placed on a comprehensive assessment of the factors that may affect the antioxidant response to mercury in fish. Antioxidant enzymes (glutathione reductase, glutathione peroxidase, and glutathione-S-transferase) did not significantly respond to mercury contamination. Levels of the analysed enzymes and oxidative damage to lipids were predominantly determined by a separate organ factor or species factor, or by the combination of both (p

Neuroblastoma is the most common cancer in infants and the fourth most common cancer in children. Aggressive cell growth and chemoresistance are notorious obstacles in neuroblastoma therapy. Exposure to the anticancer drug ellipticine inhibits efficiently growth of neuroblastoma cells and induces apoptosis in these cells. However, ellipticine induced resistance in these cells. The upregulation of a vacuolar (V)-ATPase gene is one of the factors associated with resistance development. In accordance with this finding, we found that levels of V-ATPase protein expression are higher in the ellipticine-resistant UKF-NB-4ELLI line than in the parental ellipticine-sensitive UKF-NB-4 cell line. Treatment of ellipticine-sensitive UKF-NB-4 and ellipticine-resistant UKF-NB-4ELLI cells with ellipticine-induced cytoplasmic vacuolization and ellipticine is concentrated in these vacuoles. Confocal microscopy and staining of the cells with a lysosomal marker suggested these vacuoles as lysosomes. Transmission electron microscopy and no effect of an autophagy inhibitor wortmannin ruled out autophagy. Pretreatment with a V-ATPase inhibitor bafilomycin A and/or the lysosomotropic drug chloroquine prior to ellipticine enhanced the ellipticine‑mediated apoptosis and decreased ellipticine-resistance in UKF-NB-4ELLI cells. Moreover, pretreatment with these inhibitors increased formation of ellipticine-derived DNA adducts, one of the most important DNA-damaging mechanisms responsible for ellipticine cytotoxicity. In conclusion, resistance to ellipticine in the tested neuroblastoma cells is associated with V-ATPase-mediated vacuolar trapping of this drug, which may be decreased by bafilomycin A and/or chloroquine.

Varied environmental compartments including soils are being contaminated by a myriad toxic metal(loid)s (hereafter termed as “metal/s”) mainly through anthropogenic activities. These metals may contaminate food chain and bring irreparable consequences in human. Plant-based approach (phytoremediation) stands second to none among bioremediation technologies meant for sustainable cleanup of soils/sites with metal-contamination. In turn, the capacity of plants to tolerate potential consequences caused by the extracted/accumulated metals decides the effectiveness and success of phytoremediation system. Chelation is among the potential mechanisms that largely govern metal-tolerance in plant cells by maintaining low concentrations of free metals in cytoplasm. Metal-chelation can be performed by compounds of both thiol origin (such as GSH, glutathione; PCs, phytochelatins; MTs, metallothioneins) and non-thiol origin (such as histidine, nicotianamine, organic acids). This paper presents an appraisal of recent reports on both thiol and non-thiol compounds in an effort to shed light on the significance of these compounds in plant-metal tolerance, as well as to provide scientific clues for the advancement of metal-phytoextraction strategies.

V této práci jsme se zaměřili na rozdíly mezi bakteriálních kultur E. coli, získaných ze stěrů infekčních ran pacientů ve srovnání s laboratorním E. coli. Navíc blokování proteinu odpovědné za syntézu glutathion (-glutamyl-cystein synthasy GCL) za použití 10 mM buthionin sulfoximin byla zkoumána. Každý E. coli ukázala výrazné rozdíly v rezistenci vůči antibiotikům. Podle odhodlaný odolné, E. coli byly rozděleny do experimentálních skupin na základě statistického vyhodnocení jejich vlastností jako odolnější a citlivější. Tyto skupiny byly také použity pro nalezení rozdíly mezi nimi v závislosti na glutathion dráhy o rezistenci na antibiotika. Citlivější E. coli vykazovaly stejné kinetiky glutathionu syntézy zatímco blokuje GCL (km 0,1 um), ve srovnání s non-blokování. Kromě toho, nejčastější mutace v genech glutathion syntetázy, glutathion peroxidázy a glutathionreduktasy byly pozorovány v této skupině ve srovnání s laboratorní E. coli. Skupina "odolnější" E. coli vykazovaly rozdíly v km mezi 0,3 a 0,8 uM. Počet mutací ve srovnání s E. coli laboratoře byla podstatně nižší v porovnání s jinou skupinou. In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (-glutamylcysteine synthase—GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the etermined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 M), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of “more resistant” E. coli exhibited differences in Km between 0.3 and 0.8 M. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group.

Identification of specific cell death is of a great value for many scientists. Predominant types of cell death can be detected by flow-cytometry (FCM). Nevertheless, the absence of cellular morphology analysis leads to the misclassification of cell death type due to underestimated oncosis. However, the definition of the oncosis is important because of its potential reversibility. Therefore, FCM analysis of cell death using annexin V/propidium iodide assay was compared with holographic microscopy coupled with fluorescence detection Multimodal holographic microscopy (MHM). The aim was to highlight FCM limitations and to point out MHM advantages. It was shown that the annexin V+/PI phenotype is not specific of early apoptotic cells, as previously believed, and that morphological criteria have to be necessarily combined with annexin V/PI for the cell death type to be ascertained precisely. MHM makes it possible to distinguish oncosis clearly from apoptosis and to stratify the progression of oncosis. Identifikace konkrétního druhu buněčné smrti je velmi významná pro mnoho vědců. Převládající druhy buněčné smrti mohou být detekovány metodou průtokové cytometrie (FCM). Nicméně, absence údajů o morfologii buněk vede ke špatnému určení druhu buněčné smrti kvůli podcenění onkózy. Proto do tohoto výzkumu byla zařazena multimodální holografická mikroskopie.

Interaction between semiconductor nanocrystals, cadmium telluride quantum dots (CdTe QDs) capped with mercaptosuccinic acid (MSA) and metallothionein (MT) was investigated. MSA-capped CdTe QDs were synthesized in aqueous solution. Mixture of MT and MSA-capped CdTe QDs has been investigated by various analytical methods as follows: tris-tricine gel electrophoresis, fluorescence evaluation and electrochemical detection of catalysed hydrogen evolution. The obtained results demonstrate that MSA-capped CdTe QDs and MT do not create firmly bound stabile complex. However, weak electrostatic interactions contribute to the interaction of MT with MSA-capped CdTeQDs. It can be concluded that QDs size influences the QDs and MT interaction. The smallest QDs had the highest affinity to MT and vice versa.

Herein, we describe an ultrasensitive specific biosensing system for detection of sarcosine as a potential biomarker of prostate carcinoma based on Forster resonance energy transfer (FRET). The FRET biosensor employs anti-sarcosine antibodies immobilized on paramagnetic nanoparticles surface for specific antigen binding. Successful binding of sarcosine leads to assembly of a sandwich construct composed of anti-sarcosine antibodies keeping the Forster distance (Ro) of FRET pair in required proximity. The detection is based on spectral overlap between gold-functionalized green fluorescent protein and antibodies@quantum dots bioconjugate (lex 400 nm). The saturation curve of sarcosine based on FRET efficiency (F604/F510 ratio) was tested within linear dynamic range from 5 to 50 nM with detection limit down to 50 pM. Assembled biosensor was then successfully employed for sarcosine quantification in prostatic cell lines (PC3, 22Rv1, PNT1A), and urinary samples of prostate adenocarcinoma patients. V tomto dokumentu, popíšeme ultrasensitivní specifický biosnímací systém pro detekci sarkosinu jako potenciálního biomarker karcinomu prostaty na základě Forster přenosu rezonanční energie (FRET). Pražec biosensoru zaměstnává anti-protilátku sarkosinu, která je imobilizovaná na povrchu paramagnetických nanočástic pro specifickou antigenní vazbu. Úspěšná vazba sarkosinu vede k sestavení sendvičové konstrukce složené z anti-protilátky sarkosinu, udržení Forster vzdálenost (RO) a FRET páru v požadované blízkosti. Detekce je založena na spektrálním překryvu mezi zlatem s funkčním zeleným fluorescenčním proteinem, protilátkou a kvantovými tečkami Bioconjugate (400 nm). Saturace křivky sarkosinu na základě FRET účinnosti (F604 / F510 poměr) byl testován v lineárním dynamickém rozsahu od 5 do 50 nM s detekčním limitem až do 50 pM. Montované biosenzor byl pak úspěšně použity pro sarkosinu kvantifikaci

Acetylsalicylic acid ( AcSA), or aspirin, was introduced in the late 1890s and has been used to treat a variety of inflammatory conditions. The aim of this work was to suggest electrochemical sensor for acetylsalicylic detection. Primarily, we utilized square wave voltammetry ( SWV) using both carbon paste electrode ( CPE) and of graphite pencil electrode ( GPE) as working ones to indirect determination of AcSA. The principle of indirect determination of AcSA bases in its hydrolysis on salicylic acid ( SA), which is consequently detected. Thus, we optimized both determination of SA and conditions for AcSA hydrolysis and found out that the most suitable frequency, amplitude, step potential and the composition and pH of the supporting electrolyte for the determination of SA was 260 Hz, 50 mV, 10 mV and Britton-Robinson buffer ( pH 1.81), respectively. The detection limit ( S/N = 3) of the SA was 1.3 ng/ml. After that, we aimed on indirect determination of AcSA by SWV CPE. We tested the influence of pH of Britton-Robinson buffer and temperature on yield of hydrolysis, and found out that 100% hydrolysis of AcSA was reached after 80 minutes at pH 1.81 and 90 C. The method for indirect determination of AcSA has been utilized to analyse pharmaceutical drug. The determined amount of AcSA in the pharmaceutical drug was in good agreement with the declared amounts. Moreover, we used GPE for determination of AcSA in a pharmaceutical drug. Base of the results obtained from stationary electrochemical instrument we used flow injection analysis with electrochemical detection to determine of salicylates ( SA, AcSA, thiosalicylic acid, 3,5-dinitrosalicylic acid and 5-sulfosalicylic acid - SuSA). We found out that we are able to determine all of detected salicylates directly without any pre-treatment, hydrolysis and so on at units of femtomoles per injection ( 5 mu l).

Miniaturization and integration of chemical devices into modules that are dimensionally comparable with electronic chips (Lab on Chip) is nowadays developing worldwide. The aim of our work was to suggest and optimize the best conditions for fabrication of TFT sensor due to its sensitivity and low experimental deviations. New electrochemical analytical device was developed to ensure certain known mass transport to electrodes, which is the most limiting process that influencing the response quality of the sensor. The device consists from rotating conic vessel for measured sample and stick-in thick-film sensor.. The sensors responses were tested under trace analysis of cadmium. Measurements were done also with the others electrochemical arrangements to compare with the new one. The sensor output current response dependence on the liquid velocity and geometrical arrangement within using standard electrochemical couple of potassium ferrocyanide-ferricyanide is presented. We found out that the new device with controlled flow of electrolyte to sensor worked properly and gave satisfactory results. Dnešním celosvětovým cílem je miniaturizace a integrace chemických zařízení do malých modulů které jsou rozměrově srovnatelné s elektronickými čipy (Lab on Chip). Cílem naší práce bylo navrhnout a optimalizovat co možná nejlepší podmínky pro výrobu tlustovrstvého senzoru tak, aby byl dostatečně citlivý s minimální odchylkou měření. Pro zajištění přesně definovaného přísunu hmoty k elektrodám, což je nejvíce limitujícím procesem majícím vliv na výstupní odezvu senzoru, bylo vyvinuto nové elektrochemické analytické zařízení. To se skládá z rotující konické nádobky pro uložení měřeného vzorku a do ní vloženého tlustovrstvého senzoru. Odezva senzoru byla testována na stopové analýze kadmia. Pro porovnání nového zařízení byla provedena stejná měření i na jiných elektrochemických uspořádáních. Je zde ukázána i výstupní proudová odezva senzoru v závislosti na rychlosti roztoku a geometrickém uspořádání při měření standardního elektrochemického redoxu fero-ferykyanidu draselného. Zjistili jsme, že nové zařízení s řízeným tokem elektrolytu k senzoru pracuje správně a podává uspokojivé výsledky.

Nitrosation of sulfhydryl group of glutathione, which is highly reactive and is often found conjugated to other molecules via its sulfhydryl moiety, is one of many biological effects of the nitric oxide (NO). This process may serve as a signal event and/or as a deposition of NO to S–nitrosoglutathione (GSNO). Moreover, GSNO may release NO under specific conditions. That is why NO, which has a little lifetime itself, could be distribute for longer distances within the organism. Here, we studied and compared the basic electrochemical characteristics of biological active thiol compounds (GSH, oxidized glutathione and GSNO). In addition, observation of the decomposition process of GSNO using different electrochemical techniques followed. Primarily we studied the influence of scan rate and reducing agent (Tris(2-carboxyethyl)phosphine). The CV calibration equations were linear, R.S.D. about 5%. The detection limits of GSH, GSSG and GSNO expressed as 3 S/N were 9 nM, 4 nM and 20 nM, respectively. In addition, the use of NO selective carbon fibre electrode and cyclic voltammetry for the study of GSNO decomposition catalysed by copper(II) and iron(II) followed.

Number of authors have concerned with electrochemical analysis of metallothionein. Recently new electroanalytical techniques enabling determination of MT at picomole level has been suggested. The aim of the presented work was to show advantages and disadvantages of the different electrochemical procedures, which are commonly used for the detection of MT—(i) cyclic voltammetry, (ii) differential pulse voltammetry, and (iii) Brdicka reaction. Primarily we aimed on improvement of the mentioned techniques. Using of reducing agent (tris(2-carboxyethyl)phosphine) and combination of the mentioned method with adsorptive transfer stripping technique (AdTS) were the main improvements of the voltammetric method. The detection limits of metallothionein measured by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and DPV Brdicka reaction were 0.5 pmol, 4 fmol and 10 amol, respectively. In addition AdTS DPV Brdicka reaction was used for the determination of metallothionein in human blood serum of 11-year-old girl, which were lead poisoned.

Platinum complexes play an important role in the chemotherapy of various tumour diseases. The aim of this paper was to investigate if a metallothionein (MT) modified hanging mercury drop electrode can be applied as a cisplatin electrochemical biosensor. The modification of the mercury electrode surface by MT and the determination of cisplatin were performed by adsorptive transfer stripping technique and differential pulse voltammetry. The detection limit (3 S/N) of cisplatin ([PtII(NH3)2Cl2]0) calculated from the decrease of CdT peak was about 2.5 pmol in 5 μl (0.5 μM) at the interaction time of 400 s. Moreover, we tested the influence of human blood serum as a complex biological matrix on the way of determination of cisplatin. On the basis of the obtained results we estimated that we are able to determine tens of picomoles of cisplatin (5 μl drop) in the presence of human blood serum.

In model experiment, an influence of increasing KCl doses on spring barley growth, accumulation of main mineral nutrients (N, P, K, Ca, Mg and Na) in main stalks, offshoots and roots and on yield formation and its structure was observed. Increase of weight of above-ground parts of plants was inhibited only at the beginning of experiment by increasing KCl doses, particularly, significantly lower growth of offshoots, but on the other hand production of dry weight of roots was negatively influenced during whole cultivation. Accumulation of main mineral nutrients in the plants was mostly influenced at potassium. Uptake of potassium by plant increased up to 37%. Yield of kernels was higher at variants with application of KCl but the correlation between higher K doses and the yield increase has not been statistically proved. Increase in the yield was reached by higher number of offshoots, higher number of kernels and higher weight of kernels in comparison with control. Content of main mineral nutrients in kernel was not influenced by application of KCl, but potassium content in straw was significantly increased.

Presence of mutated and/or structurally modified (e.g., denatured, aggregated) protein p53 form is associated with several disorders such as Alzheimer's disease, Parkinson's disease, prion diseases, and many types of tumours. The aim of this work was to distinguish native, denatured and aggregated form of full-length p53 by flow injection analysis coupled with electrochemical detector (FIA-ED). Firstly FIA-ED method used for protein native form determination was optimized (detection limit 45.8 amol per 5 mul injection; 3 x S/N). In addition the technique was applied to identify p53 structural forms (denatured and aggregated). It was found out that denatured form provides about three times higher electrochemical response (protein structure unfolding, approach of more electroactive centers - aminoacid residues - towards electrode surface) in comparison with native form. On the other hand, aggregated form offers lower response (steric eclipse of electroactive protein parts) when compared with the signal of native form. The obtained data show that we are not only able to sensitively determine native, denatured, and aggregated structural forms of p53 protein but also to distinguish them.

Metallothioneins belong to the group of intracellular, high molecular and cysteine-rich proteins whose content increase with increasing concentration of a heavy metal. Here we applied the adsorptive transfer stripping differential pulse voltammetry Brdicka reaction for the determination of metallothionein in human blood serum of patient poisoned by lead and/or treated by platinum. The increased metallothionein concentrations in both cases were observed.

Image analysis (IA) was used to determine the areas and circumferences of clusters of early somatic embryos (ESEs) of the Norway spruce (Picea abies /L./Karst.). Results obtained from IA were compared with the fresh weights of the ESE clusters and their esterase activities. The areas of the ESE clusters correlated well with both the increases in fresh weight (R 2=0.99) of the ESEs and their esterase activities (R 2=0.99). In addition, we studied the viability of the ESEs, which was determined by (a) double staining with fluorescein diacetate and propidium iodide (the resulting fluorescence was quantified by IA) and (b) determining esterase activity using a spectrofluorimetric detector. The results obtained with IA and esterase assay were comparable (the deviation between the tangents of the bisectors was 6.4%). IA was also used to study the effect of Pb–EDTA chelate (50, 250 and 500 μM) on the viability of the ESEs and on the growth of clusters. The presence of Pb–EDTA markedly slowed the growth of ESEs clusters (by more than 65% with 250 μM of Pb–EDTA after 288 h of cultivation) and decreased the viability of ESEs (by more than 30% with 500 μM of Pb–EDTA after 288 h of cultivation). The lead concentration in the ESEs was determined by differential pulse anodic stripping voltammetry and increased with the external lead concentration and the time of treatment from 100 to 600 pg Pb/100 mg of fresh weight of ESEs. Glutathione is a diagnostic marker of the influence of Pb–EDTA on ESEs and its content was determined by high–performance liquid chromatography coupled with mass spectrometry. The glutathione content changed linearly with treatment time and the applied external lead concentration. The highest glutathione content was obtained at 250 μM of Pb–EDTA after 192 h of cultivation.

A fast determination of isoflavones (genistin, genistein, daidzein, daidzin, glycitin, glycitein, ononin, formononetin, sissotrin and biochanin A) by HPLC/UV-vis-DAD working at 254 nm is described. An Atlantis dC18 fast reversed-phase chromatographic column (20 mm x 2.1 mm, 3 microm particle size) was used at a flow rate 0.35 ml min(-1) of a mobile phase consisted from 0.1% (v/v) acetic acid (A) at pH 3.75 and methanol. (B). A linear gradient profile was used for separation at the column temperature 36 degrees C. Limits of detection (LODs for 3 S/N criterion) per sample injection (5 microl) ranged from 166.2 to 17.0 fmol (9.4-1.1 ng ml(-1) for biochanin A and genistin, respectively. The recoveries 96-106% were obtained for the different concentrations of the isoflavones (RSDs 2-8%). The pressurized liquid extraction/HPLC/UV-vis-DAD method was used for the determination of the isoflavones in soy bits (28-962 microg g(-1) dry weight). The proposed procedure is faster (ca. 8 min) without loosing its separation efficiency (up to 10 isoflavonoids can be determined) and sensitivity (tens to hundreds fmol).

Growth is one of the basic properties of biological systems. The methods which are commonly used for the determination of growth are usually difficult and not very accurate. In the present work we decided to use esterase activity as a growth marker in tobacco suspension culture (BY-2 line) and in early somatic embryos of Norway spruce (clone 2/32) grown on a semi-solid medium. Esterase activity correlates well with the classical growth characteristics of BY-2 and spruce early somatic embryos. Determination of esterase activity is based on spectrophotometric and spectrofluorimetric detection of reaction products, which arise from the enzymatic hydrolysis of two substrates (p -nitrophenyl acetate and fluorescein diacetate) by esterase. The spectrophotometric method enabled us to detect approximately 104 BY-2 cells and 25 spruce embryos whereas the more sensitive spectrofluorimetric method allowed us to detect approximately 800 BY-2 cells and 5 early somatic embryos of Norway spruce.

Water- and fat-soluble vitamins were separated on a MetaChem Polaris C18-A ( 150 mm ×4.6 mm, 3 μm particle size) in a single run using combined isocratic and linear gradient elution with a mobile phase consisting of 0.010% trifluoroacetic acid of pH 3.9 (solvent A) and methanol (solvent B) at the flow rate 0.7 ml min −1 . A linear gradient profile (A:B) started at 95:5 and was constant in the first 4 min, then linearly decreased up to 2:98 during the next 6 min, then it was constant in the next 20 min and finally linearly increased up to 95:5 ratio of water phase in the last 5 min of the separation. The most suitable detection wavelength for simultaneous vitamin determination was 280 nm. The method was applied for the solid sample of pharmaceutical preparation (B-Komplex), fortified powdered drinks (multi-vitamin) and food samples. The results were in good agreement with the declared values.

A newly elaborated accelerated solvent extraction (ASE) procedure allowed more accurate (

Azidothymidine (AZT, 3'-azido-3'-deoxythymidine, Zidovudine, Retrovir) is an approved and widely used antiretroviral drug for the treatment of human immunodeficiency virus (HIV) infection. Dynamic electrochemical methods have been employed for the fast and inexpensive determination of this drug in natural samples. The electrochemical signal of AZT, resulting from the reduction of azido group, was studied by square wave voltammetry (SWV), linear sweep voltammetry (LSV) and elimination voltammetry with linear scan (EVLS) using a hanging mercury drop electrode (HMDE). This paper explores the possibility of determining AZT in the presence of native (dsDNA) or denatured calf thymus DNA (ssDNA), and/or some synthetic oligodeoxynucleotides (ODNs). The detection limit of AZT in the absence and in the presence of ssDNA (10 microg/ml) is 1 and 250 nM, respectively. It was found that the signal of AZT is not substantially affected by the presence of DNA. We can therefore assume that the electrons are transferred through the adsorption layer of nucleic acids. By using the elimination procedure, both irreversible reduction signals of AZT and DNA are augmented. Moreover, the elimination signal in the peak-counterpeak form may indicate the adsorption of the analytes on the electrode surface preceding an electron transfer.

In this work we established differential pulse anodic stripping voltammetry (DPASV) as the tool for analysis of lead in the plant cell culture. For the cultivation procedure, lead in Pb(II)-ethylenediaminetetraacetic acid (Pb-EDTA) chelate has been used. The detection limit of lead was found at 500 pM in phosphate buffer (pH 5.5), and 100 nM in prepared cells intracellular extract (20 pg Pb(II)/mg cells). For determination of cysteine-rich peptides, voltammetry in differential mode (DPV) in cobalt(III)-containing ammonia buffer (Brdicka reaction) was used. In this short communication, we present suitable voltammetric techniques for the physiological study of lead and thiols in plant cell culture.

The azido-deoxythymidine (AZT, Zidovudine) is an antiproliferative and virostatic drug widely used in human immunodeficiency virus type 1 (HIV-1) infection treatment. With respect to side effects of high doses and a short half-life of AZT, a fast and simple detection method for this agent could be helpful. The aim of our study was to determine AZT levels in natural samples (urine, serum, whole blood, and cell cultures, such as the HaCaT line of keratinocytes) without their mineralization and/or purification, by means of electrochemical methods using hanging mercury drop electrode (HMDE). On this electrode, AZT undergoes irreversible reduction at the peak potential near Ep -1.1 V (vs. Ag/AgCl/3M KCl). Reduction AZT signals were measured by cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and constant current chronopotentiometric stripping analysis (CPSA). In phosphate buffer (pH 8) the SWV yielded the best AZT signal with the detection limit of 1 nM. The determination of AZT concentration in biological materials is affected by electroactive components, such as proteins and DNA. For monitoring the influence of these compounds, AZT reduction was performed in the presence of 10 mg/mL calf thymus ssDNA and/or 100 mg/mL bovine serum albumin. In these cases, the detection limit increased to 0.25 mM. Also studied was the AZT concentration in keratinocyte cells was followed during cell cultivation. It has been shown that the SWV may be considered as a useful tool for the determination of AZT concentration in cell cultures, and for monitoring AZT pharmacokinetics.

Use of square-wave voltammetry (SWV) for determination of cefoperazone (CFPZ) in some buffers, bacterial culture, urine, and milk is described. CFPZ provides a specific voltammetric signal which is affected by pH and solution components. Determination of CFPZ in Britton-Robinson buffer, pH 4.4, is sensitive with a low detection limit (about 0.5 nmol L(-1)). In a more complex medium (bacterial 2YT medium, pH 7.2) the detection limit was approximately 1.5 micromol L(-1). We provide evidence that SWV is a suitable and quick method for CFPZ determination in a culture of living bacteria without separation of biomass. We have found big differences between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) in cultivation in the presence of CFPZ, depending on time. When CFPZ is cleaved by penicillinase, a new SWV peak b appears at more positive potentials. This peak rises both with increasing concentration of enzyme and with cleavage time while the original CFPZ peak is simultaneously decreasing. We determined the concentration of CFPZ in the drug Pathozone by the standard addition method and achieved good agreement with the declared value of CFPZ in the drug. With a simple pretreatment procedure it is possible to determine CFPZ in milk; for urine no pretreatment was required. Using SWV we could detect CFPZ concentrations as low as 500 nmol L(-1) in bovine milk and human urine.

Due to the considerable stability of green fluorescent proteins and their capacity to be readily permutated or mutated, they may be exploited in multiple ways to enhance the functionality of in vitro biosensors. Many possibilities, such as the formation of chimeras with other proteins or antibodies, as well as Förster resonance emission transfer performance, may be used for the highly sensitive and specific detection of the target molecules. This review considers the great potential of green fluorescent proteins as the fluorescent probing or recognition biomolecule in various in vitro biosensors applications, as well as obstacles associated with their use.

Nanoparticles of metals interacting with cellular components and biomacromolecules including DNA and RNA alter cellular processes. From the point of view of the antimicrobial activity, the metal nanoparticles at nanomolar concentrations exhibit excellent results on the inhibition of bacterial strains. The general mechanism of metal nanoparticles action has not been fully understood yet; however, several currently accepted schemes include damaging of the microbial enzymes by the release of metal ions, changing the integrity of the membrane, penetration into the bacterial cytoplasm, and accumulation in the periplasmic space or the formation of reactive oxygen species by the effect of metal nanoparticles. Moreover, Gram-positive bacteria react significantly later on the effect of metal nanoparticles than Gram-negative bacteria, which is reflected with the later inhibition of cell division. The aim of this study is to describe the properties of metal nanoparticles (silver, selenium, copper, or zinc nanoparticles) and to compare their antimicrobial properties in a complex with chitosan on the bacterial strains Staphylococcus aureus and Escherichia coli.

Background The environmental impacts of various substances on all levels of organisms are under investigation. Among these substances, endocrine-disrupting compounds (EDCs) present a threat, although the environmental significance of these compounds remains largely unknown. To shed some light on this field, we assessed the effects of 17 beta-oestradiol on the growth, reproduction and formation of free radicals in Eisenia fetida. Methodology/Principal Findings Although the observed effects on growth and survival were relatively weak, a strong impact on reproduction was observed (50.70% inhibition in 100 mu g/kg of E-2). We further demonstrated that the exposure of the earthworm Eisenia fetida to a contaminant of emerging concern, 17 beta-oestradiol (E2), significantly affected the molecules involved in antioxidant defence. Exposure to E2 results in the production of reactive oxygen species (ROS) and the stimulation of antioxidant systems (metallothionein and reduced oxidized glutathione ratio) but not phytochelatins at both the mRNA and translated protein levels. Matrix-assisted laser desorption/ionization (MALDI)-imaging revealed the subcuticular bioaccumulation of oestradiol- 3,4-quinone, altering the levels of local antioxidants in a time-dependent manner. Conclusions/Significance The present study illustrates that although most invertebrates do not possess oestrogen receptors, these organisms can be affected by oestrogen hormones, likely reflecting free diffusion into the cellular microenvironment with subsequent degradation to molecules that undergo redox cycling, producing ROS, thereby increasing environmental contamination that also perilously affects keystone animals, forming lower trophic levels.

In this study a device for automatic electrochemical analysis was designed. A three electrodes detection system was attached to a positioning device, which enabled us to move the electrode system from one well to another of a microtitre plate. Disposable carbon tip electrodes were used for Cd(II), Cu(II) and Pb(II) ion quantification, while Zn(II) did not give signal in this electrode configuration. In order to detect all mentioned heavy metals simultaneously, thin-film mercury electrodes (TFME) were fabricated by electrodeposition of mercury on the surface of carbon tips. In comparison with bare electrodes the TMFEs had lower detection limits and better sensitivity. In addition to pure aqueous heavy metal solutions, the assay was also performed on mineralized rock samples, artificial blood plasma samples and samples of chicken embryo organs treated with cadmium. An artificial neural network was created to evaluate the concentrations of the mentioned heavy metals correctly in mixture samples and an excellent fit was observed (R2 = 0.9933). V této studii byla navržena automatická elektrochemická analýza. Detekční systém složený ze tří elektrod byl připojen k polohovacímu zařízení, které nám umožnilo manipulaci s elektrodou z jedné jamky na druhou mikrotitrační destičky. Jednorázový uhlíkový tip elektrody byl použit pro kvantifikaci Cd (II), Cu (II) a Pb (II) iontů, zatímco Zn (II) neměl signál v této konfiguraci elektrody. Aby bylo možné odhalit všechny uvedené těžké kovy současně pomocí tenkovrstvé rtuťové elektrody (TFME), byly vyrobeny podle elektrodepozicí rtuti na povrchu hrotů uhlíku. Ve srovnání s holýma elektrodami se TMFEs měli nižší detekční limity a lepší citlivost. Kromě čistého vodného roztoku těžkých kovů ....

Nanoparticles as a progressively developing branch offer a tool for studying the interaction of carbon quantum dots (CQDs) with DNA. In this study, fluorescent CQDs were synthesized using citric acid covered with polyethylene glycol (PEG) as the source of carbon precursors. Furthermore, interactions between CQDs and DNA (double-stranded DNA and single-stranded DNA) were investigated by spectral methods, gel electrophoresis, and electrochemical analysis. Primarily, the fluorescent behavior of CQDs in the presence of DNA was monitored and major differences in the interaction of CQDs with tested single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) were observed at different amounts of CQDs (µg mL−1: 25, 50, 100, 250, 500). It was found that the interaction of ssDNA with CQDs had no significant influence on the CQDs fluorescence intensity measured at the excitation wavelengths of 280 nm, 350 nm, and 400 nm. However, in the presence of dsDNA, the fluorescence intensity of CQDs was significantly increased. Our results provide basic understanding of the interaction between CQDs and DNA. Such fabricated CQDs-DNA might be of great benefit for the emerging nanomaterials based biosensing methods.

In most of the currently developed electrochemical DNA hybridization sensors short single-stranded probe DNA is immobilized on an electrode and both the hybridization and detection steps are carried out on the electrode surface. Here we use a new technology in which DNA hybridization is performed on commercially available magnetic beads and detection on solid electrodes. Paramagnetic Dynabeads Oligo(dT)25 (DBT) with covalently bound (dT)25 probe are used for the hybridization with target DNA containing adenine stretches. Target DNA is modified with osmium tetroxide,2,2′-bipyridine (Os,bipy) and the immunogenic DNA-Os,bipy adduct is determined by the enzyme-linked immunoassay with electrochemical detection. Electroinactive 1-naphthyl phosphate is used as a substrate and the electroactive product (1-naphthol) is measured on the carbon electrodes. Alternatively Os,bipy-modified target DNA can be determined directly by measuring the osmium signal on the pyrolytic graphite electrode (PGE). A comparison between determinations of the 67-mer oligodeoxynucleotide on carbon electrodes using (a) the guanine oxidation signal, (b) direct determination of the DNA-Os,bipy adduct and (c) its electrochemical immunoassay showed immunoassay to be the most sensitive method. In combination with DBT, the DNA hybridization of long target deoxyoligonucleotides (such as 67- and 97-mers) and a DNA PCR product (226-base pairs) have been detected by immunoassay at high sensitivity and specificity.

Complexes of osmium tetroxide with nitrogen ligands were developed and used in our laboratory as probes of the DNA structure. Here, we show that the complex of osmium tetroxide with 2,2′-bipyridine (Os,bipy) can be used for modification and electrochemical detection of proteins at neutral pH. Salmon luteinizing hormone (SLH) containing two tryptophan (Trp) residues and human luteinizing hormone (HLH) containing one Trp were modified by Os,bipy and measured by differential pulse adsorptive stripping voltammetry (DPAdSV) at a hanging mercury drop electrode (HMDE). The intensity of the DPAdSV catalytic signals corresponded to the number of Trp residues in the peptide molecule. Decreasing pH of the background electrolyte from 6.6 to 3.8 led to the increase of DPAdSV signals, suggesting that at pH 3.8, the DPAdSV detection limit might be well below 1 ng/ml. Our results suggest that Os,bipy is potentially useful for chemical modification of proteins.

Use of the silver electrode as a sensor for the monitoring of zinc in cell growth medium is described. Zinc at silver electrodes provides specific voltammetric signal, which is affected by solution components. Signals of zinc ions in phosphate buffer solutions with and without cell growth medium were compared. Common DMEM cell culture medium was used for the cultivation of a cell line of v-myb-transformed chicken monoblasts and its variants expressing v-jun and c-jun in a zinc-dependent manner. Electrochemical results showed zinc concentrations in the medium coincide very well with the jun expression. With respect to the low toxicity of silver for eukaryotic cells, silver electrodes represent promising tools for the determination of zinc concentrations in vivo without the potential risk of a cell culture damage.

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.

Cisplatin belongs to the most widely used cytostatic drugs. The determination of the presence of the DNA-cisplatin adducts may not only signal the guanine-rich regions but also monitor the interaction reaction between DNA and the drug in terms of speed of interaction. In this work, the combined advantages of magnetic particles-based isolation/purification with fluorescent properties of quantum dots (QDs) and antibodies targeted on specific recognition of DNA-cisplatin adducts are demonstrated. The formation of a complex between magnetic particles with surface modified by anti-dsDNA antibody, cisplatin-modified DNA and QDs labelled anti-cisplatin-modified DNA antibody was suggested and optimized.

The platinum group elements are significant compounds used in numerous fields of human life. Besides of often discussed toxic effect the platinum compounds show the therapeutic effects. Nowadays, platinum-based cytostatic are still the most frequently used drugs in oncology. Due to their proved medicinal purposes the behavior in the organism should to be intensively studied as well as their interactions with DNA and other important biological molecules. This review summarizes the recent results in the platinum drug field and discusses the behavior of platinum compounds in cells. The interaction of platinum and DNA with respect to the change of the DNA structure are also clarified.

The present work is aimed to synthesize CdTe/ZnSe core/shell quantum dots (QDs) in an easy way and to explore the possibilities of its application in in vitro imaging of chicken tissue and embryo. The QDs were prepared using microwave irradiation with different temperatures, which is a very easy and less time-consuming method. Subsequently, these QDs were characterized by spectrofluorimetry, Transmission Electron Microscopy, X-ray fluorescence analysis and Dynamic Light Scattering measurement. A blueshifting of the emission was found when ZnSe was deposited on CdTe QDs. The QDs showed its fluorescence emission quantum yields up to 25%. They were applied into chicken embryos and breast muscle tissues to study their efficiency in in vitro imaging. All the QDs of different color were able to visualize in in vitro imaging. The highest fluorescence intensity was detected in the case of red QDs prepared at 100°C. The green and red QDs were possible to detect up to the depth of 3 and 4 mm of the tissue, respectively.

MicroRNAs (miRNAs) are becoming a very important group of molecules especially since their connection to numerous diseases has been revealed. The potential in gene therapy as well as in diagnostics is being widely investigated leading to the demand of sensitive, selective and simple methods of isolation and detection. The combined advantages of magnetic particle-based separation with sensitive electrochemical detection may offer a very valuable tool for these purposes. In this study, the miR‑124 was targeted as an example analyte for development and optimization of the isolation procedure coupled to the electrochemical detection. The sensitivity of the method was demonstrated by the limit of detection at the level of nanomolar concentration (4 nM). To verify the applicability of the procedure to the real samples, miR‑124 was isolated from the human embryonic kidney cells naturally expressing this miRNA molecule and the results were compared to the amount of miR‑124 isolated from the cells transfected by the pENTR-miR‑124 plasmid leading to the overexpression of miR‑124.

Zinc(II) ions are important components of many proteins and are involved in numerous cellular processes such as apoptosis or drug resistance. Prostate cancer has a unique relationship with zinc(II) ions. However, the relationship was examined only in short-term zinc(II) treatments. Therefore, the aim of this study was to create zinc-resistant prostatic cell lines at various stages of the disease (22Rv1 and PC-3) and a normal prostate epithelium (PNT1A) using a long-term zinc exposure. Consequently, the expression profile of the following genes was analyzed: BAX, Bcl-2, Beclin-1, CFLAR, HIF1α, KRAS, mTOR, MT1A, MT2A, NF-κB1, p53, survivin, ZIP1, ZnT-1. The resistance was verified using the MTT test; on average a 1.35-fold lower zinc(II) toxicity (higher IC50) was determined in zinc(II)-resistant cells. The associated resistance to cisplatin was also determined; IC50 for cisplatin was 1.52-fold higher. With regard to the gene expression profiles, our results indicate that differential mechanisms participate in the short-term zinc toxicity regulation and long-term resistance; the short-term treatment was associated with MT2A (p < 0.001), ZnT-1 (p < 0.001), and MT1A (p < 0.03) and the long-term resistance was associated particularly with NF-κB1 (p < 0.001), CFLAR (p < 0.001), KRAS (p < 0.001), p53 (p < 0.002), survivin (p = 0.02), ZIP1 (p = 0.002), BAX (p = 0.005), and HIF1α (p = 0.05). Therefore, the KRAS-PI3K-NF-κB pathway is expected to play a crucial role in the regulation of zinc resistance. In summary, compared to previous studies, identical mechanisms of resistance were demonstrated on multiple cell lines, both non-tumor and tumorous, derived both from primary and advanced secondary sites.

The complexes of Fe(II), Mn(II) and Ni(II) with a combination of a Schiff base, nitrogen-donor ligand or macrocyclic ligand and trithiocyanuric acid (ttcH3) were prepared and characterized by elemental analysis and spectroscopies. Crystal and molecular structures of the iron complex of composition [Fe(L1)](ttcH2)(ClO4) EtOH H2O (1), where L1 is Schiff base derived from tris(2-aminoethyl)amine and 2-pyridinecarboxaldehyde, were solved. It was found that the Schiff base is coordinated to the central iron atom by six nitrogens forming deformed octahedral arrangement, whereas trithiocyanurate(1-) anion, perchlorate and solvent molecules are not coordinated. The X-ray structure of the Schiff base sodium salt is also presented and compared with the iron complex. The anticholinesterase activity of the complexes was also studied. Komplexy Fe (II), Mn (II) a Ni (II), s kombinací Schiffovy bází, dárce dusíku ligand nebo makrocyclický ligand a kyselina trithiocyanuric (ttcH3) byly připraveny a charakterizovány pomocí elementární analýzy a spektroskopie.Byly zde řešeny krystaly a molekulární struktury komplexu železa o složení [Fe (L1)] (ttcH2) (ClO 4) EtOH H 2O (1), kde L1 je Schiffovy báze odvozené od tris (2-aminoethyl) amin a 2-pyridinkarboxaldehydu. Bylo zjištěno, že Schiffova báze je koordinována na centrálním atomu železa šesti atomy dusíku tvořenou deformovanou osmibokou přípravou, zatímco trithiocyanurate (1) aniontu,chloristanové a molekuly rozpouštědla nejsou koordinovány.X-ray struktura Schiff na bázi solného sodíků jsou prezentovány ve srovnání s komplexy železa. Byly také studovány Inhibitory aktivita komplexů.

There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 mu M) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. K dispozici je vznikající a pokud jde o problém v oblasti bakteriální rezistence, což je potvrzeno počtu úmrtí souvisejících s drogami odolné proti bakteriálním infekcím. Cílem této studie bylo porovnat účinky antibiotik na kmen bez rezistentní Staphylococcus aureus a kmenů rezistentních k kadmia nebo olova ionty. Kmeny odolného kovu byly vytvořeny postupným přidáváním 2 mM roztoku kovových iontů (kadmium nebo olovo) na S. aureus kultury.Zvyšující antimikrobiální účinek ampicilin, streptomycin, penicilin a tetracyklin (0, 10, 25, 50, 75, 150, 225 a 300 um) na rezistentních kmenů byla pozorována za použití metody růstových křivek. Významná inhibice růstu (ve srovnání s kontrolou) buněk rezistentních kadmia byl pozorován v přítomnosti všech čtyř různých antibiotik. Na druhé straně, přidání streptomycinu a ampicilinu neinhibuje růst olova rezistentního kmene. Další antibiotika stále toxické pro bakteriálních buněk. Významné rozdíly v morfologii buněčných stěn byly označeny změny ve tvaru buňky. Naše data ukazují, že přítomnost kovových iontů v městském prostředí, může přispět k rozvoji bakterií kmene rezistence na jiné látky, včetně antibiotik, které by mohly mít vliv na veřejné zdraví. (přeloženo strojově, pravopis nekontrolován).

We evaluated photosynthetic reactions in Acer campestre L. in a multi-factorial field experiment near Hodonin, Southern Moravia, Czech Republic. In this experiment, selected plots were amended with three different supplementary soil substances, that is, zeolite, lignite, and hydroabsorbent Agrisorb , and were compared with unamended control plots. Microclimatic parameters, that is, temperature, relative humidity, soil moisture, and solar radiation were measured. In the spring of 2008, supplementary soil substances were applied, and in the autumn of the same year, experimental A. campestre L. plants were harvested. The basic physiological parameters, chlorophyll content and fluorescence, stomatal conductance, and sap flow were determined in the experimental plants. Determination of the above-mentioned parameters showed higher vitality of plants cultivated on plots supplemented by lignite, followed by zeolite. In comparison with the control plants, the application of lignite led to increase of average chlorophyll content and fluorescence by 37 and 20%, respectively, stomatal conductance by 29%, and sap flow by 44% in plants. In comparison with the control plants, the application of zeolite resulted in the enhancement of average chlorophyll content and fluorescence by 14 and 15%, respectively, stomatal conductance by 16%, and sap flow by 36% in plants. The monitored parameters of plants cultivated on plots supplemented with hydroabsorbent Agrisorb were similar to those measured in control plants. In addition, the results obtained are related to actual weather. Correlations between type of the applied supplementary soil substances, soil moisture, and physiological parameters were found. Data of short-time measurement of photosynthesis response correspond with data of long-time measurement of morphological characteristics. The highest height increments were determined in experimental group cultivated under lignite application, followed by zeolite. Statistically insignificant plant height increases were observed in plants cultivated on the soil supplemented with hydroabsorbent Agrisorb . Key words: Abiotic stress, soil conditions, microclimatic data, photosynthetic reactions, morphological characteristic, environmental sensors.

Introduction Heavy Metals in Contaminated Soils: A Review of Sources, Chemistry, Risks and Best Available Strategies for Remediation, Raymond A. Wuana and Felix E. Okieimen Heavy Metal Contamination Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain, Shun-an Zheng, Xiangqun Zheng, and Chun Chen Spatially Explicit Analysis of Metal Transfer to Biota: Influence of Soil Contamination and Landscape, Clementine Fritsch, Michael Coeurdassier, Patrick Giraudoux, Francis Raoul, Francis Douay, Dominique Rieffel, Annette de Vaufleury, and Renaud Scheifler Heavy Metal Contamination of Soil and Sediment in Zambia, Yoshinori Ikenaka, Shouta M. M. Nakayama, Kaampwe Muzandu, Kennedy Choongo, Hiroki Teraoka, Naoharu Mizuno, and Mayumi Ishizuka Human Exposure Pathways of Heavy Metals in a Lead-Zinc Mining Area, Jiangsu Province, China, Chang-Sheng Qu, Zong-Wei Ma, Jin Yang, Yang Liu, Jun Bi, and Lei Huang Analysis and Assessment of Heavy Metal Contamination Integrated Assessment of Heavy Metal Contamination in Sediments from a Coastal Industrial Basin, NE China, Xiaoyu Li, Lijuan Liu, Yugang Wang, Geping Luo, Xi Chen, Xiaoliang Yang, Bin Gao, and Xingyuan He A Determination of Metallothionein in Larvae of Freshwater Midges (Chironomus riparius) Using Brdicka Reaction, Ivo Fabrik, Zuzana Ruferova, Klara Hilscherova, Vojtech Adam, Libuse Trnkova, and Rene Kizek Multivariate Statistical Assessment of Heavy Metal Pollution Sources of Groundwater Around a Lead and Zinc Plant, Abbas Ali Zamani, Mohammad Reza Yaftian, and Abdolhossein Parizanganeh Assessment of Heavy Metal Contamination of Agricultural Soil around Dhaka Export Processing Zone (DEPZ), Bangladesh: Implication of Seasonal Variation and Indices, Syed Hafizur Rahman, Dilara Khanam, Tanveer Mehedi Adyel, Mohammad Shahidul Islam, Mohammad Aminul Ahsan, and Mohammad Ahedul Akbor Remediation of Heavy Metal Contamination Phytoremediation of Heavy Metals: A Green Technology, P. Ahmadpour, F. Ahmadpour, T. M. M. Mahmud, Arifin Abdu, M. Soleimani, and F. Hosseini Tayefeh Assessment of the Efficacy of Chelate-Assisted Phytoextraction of Lead by Coffeeweed (Sesbania exaltata Raf.), Gloria Miller, Gregorio Begonia, Maria Begonia, Jennifer Ntoni, and Oscar Hundley Sustainable Sources of Biomass for Bioremediation of Heavy Metals in Waste Water Derived from Coal-Fired Power Generation, Richard J. Saunders, Nicholas A. Paul, Yi Hu, and Rocky de Nys Characterization of the Metabolically Modified Heavy Metal-Resistant Cupriavidus metallidurans Strain MSR33 Generated for Mercury Bioremediation, Luis A. Rojas, Carolina Yanez, Myriam Gonzalez, Soledad Lobos, Kornelia Smalla, and Michael Seeger A Ferritin from Dendrorhynchus zhejiangensis with Heavy Metals Detoxification Activity, Chenghua Li, Zhen Li, Ye Li, Jun Zhou, Chundan Zhang, Xiurong Su, and Taiwu Li Index

Metallothionein (MT) from rabbit liver was analyzed by differential pulse polarography, cyclic voltammetry, square wave voltammetry, and chronopotentiometric stripping analysis (CPSA) with a hanging mercury drop electrode under various conditions. The highest sensitivity of the MT determination was obtained with CPSA which produced a well-developed peak H due to catalytic hydrogen evolution at highly negative potentials. The highest peak H was obtained in borate buffer close to pH 8.0. In this medium, subnanomolar concentrations of MT were detectable. In the adsorptive transfer stripping (medium exchange) experiments, determination of few femtomoles of MT in 5-microL aliquots of the analyte was possible. CPSA determination of MT in various tissues of carp (Cyprinus carpio) yielded values in agreement with the published data.

A new method for the simultaneous determination of adenine and cytosine is described. Multivariate calibration based on a suitable experimental design (ED) and soft modeling with artificial neural networks (ANNs) is used for quantitative analysis of overlapped linear scan voltammetric (LSV) and differential pulse polarographic (DPP) peaks of adenine and cytosine that occur in the region of hydrogen evolution. It is demonstrated that analysis of mixtures, even if some of the constituents undergo an irreversible reduction, can be quantified with reasonable accuracy. The average absolute error was estimated as 3.7% in LSV, 4.6% in DPP for adenine and 5.2% in LSV, 5.9% in DPP for cytosine. For the whole testing set the comparison of the added and found values of adenine and cytosine concentrations was characterized by an agreement factor (about 0.06). The method is quite general and can be used for analysis of other biologically important substances without their separation.

Adsorptive stripping voltammetry has been extended by elimination voltammetry with linear scan rate (EVLS). EVLS offers the elimination of selected currents from the linear scan voltammetry results. It can be achieved by an elimination function formed by a linear combination of total currents measured at different scan rates, because the basic idea of elimination of chosen currents (for example the charging current, I-c, the reversible current for substances transported only by linear diffusion, I-r, and the purely kinetic current, I-k) consists of the different dependence of voltammetric current on the scan rare. In this article, the problem of substance adsorption influence on the elimination voltammetry results has been studied. Theoretical curves of an irreversible current with adsorbed substance being electroactive were calculated for three elimination functions. A: the function eliminating I-k and I-c and conserving I-r B: the function eliminating I-c and I-r. conserving I-k; and C: the function eliminating I-r and I-k and conserving I-c, where I-c, I-r, and I-k are the charging current, the reversible diffusion current, and the kinetic current, respectively. A larger difference between diffusion and adsorption was exhibited by the elimination function A. It provides a substantial increase in resolution and sensitivity as compared to the linear scan voltammetry current peak and clearly marks the adsorption. In case of the adsorption of electroactive substances this elimination function A can be useful for analytical applications, particularly for the adsorptive stripping voltammetry with electrochemical irreversible systems. As a practical application, the adsorptive stripping voltammetry of thermally denatured DNA on a hanging mercury electrode has been developed. While the LSV signal of single-stranded DNA at low concentrations gives a slight hint of the cathodic peak (due to the reduction of adenine and cytosine residues), the elimination A provides quite a clear signal in the form of the peak-counterpeak. It is possible to determinate DNA at concentrations below micrograms per milliliter by using this elimination function. The results received by the adsorptive stripping voltammetry in the mode of linear scan (LSV), square-wave (SWV) and elimination with linear scan (EVLS) are discussed.

Summary Glutathione belongs to a vital intra- and extra-cellular protective antioxidant and is found almost exclusively in its reduced form. The ratio between its reduced and oxidized within cells is often used as a marker of cellular toxicity. The objectives of the study were to (i) determine both the reduced (GSH) and oxidized glutathione (GSSG) and cysteine (Cys) in the sperm of the Acipenser baerii and Acipenser ruthenus ,a s well as in Perca fluviatilis and Sander lucioperca, and (ii) to demonstrate the differences in concentration levels between representatives of acipenseriform and teleost species. High performance liquid chromatography with electrochemical detection was employed. The average content of the thiols determined in the sperm samples were as follows: Acipenser baerii (cysteine 55 ± 8 l gm l )1 ; GSH 126 ± 19 l gm l )1 ; GSSG 49 ± 7 l gm l )1 ), Acipenser ruthenus (cysteine 62 ± 9 l gm l )1 ; GSH 768 ± 115 l gm l )1 ; GSSG 180 ± 16 l gm l )1 ), Sander lucioperca (cysteine 251 ± 38 l gm l )1 ; GSH 185 ± 28 l gm l )1 ; GSSG 93 ± 14 l gm l )1 ), Perca fluviatilis (cysteine 281 ± 42 l gm l )1 ; GSH 496 ± 74 l gm l )1 ; GSSG 138 ± 21 l gm l )1 ). Based on the results obtained it can be concluded that this method is sensitive and selective for the determination of these compounds in real samples. Results revealed differences in cysteine content between species of the two systematic categories but also showed that ratios between GSH and GSSG can vary between species while potentially predict oxidative stress in fish sperm.

Electrophoretic mobility shift assay (EMSA) is a well-established technique to monitor interactions between biomolecules particularly DNA and proteins. Even though numerous variations of this method have been presented, challenges in the form of detection sensitivity and/or variations in the stability of the formed complex still remain. With advances in the area of nanomaterials improvements in EMSA have been also suggested. Recently, Zhang and Wang (Electrophoresis 2015, 36, 1011-1015) presented electrophoretic mobility shift method for determination of number of DNA molecules conjugated to quantum dots (QDs), which was further utilized for calculation of enzymatic activity, sequence specific DNA detection, and neutral molecule quantification.

Algal biomass that is represented mainly by commercially grown algal strains has recently found many potential applications in various fields of interest. Its utilization has been found advantageous in the fields of bioremediation, biofuel production and the food industry. This paper reviews recent developments in the analysis of algal biomass with the main focus on the Laser-Induced Breakdown Spectroscopy, Raman spectroscopy, and partly Laser-Ablation Inductively Coupled Plasma techniques. The advantages of the selected laser-based analytical techniques are revealed and their fields of use are discussed in detail. Biomasa řas, zastoupena převážně komerčně prodokovanými druhy řas, nachází v poslední době uplatnění v potenciálních průmyslových odvětvích. Tato biomasa může být vhodně použita pro bioremediaci, produkci biopaliv a v potravinářství. Předložený článek shrnuje aktuální pokrok v analýze biomasy řas se zaměřením na spektroskopii laserem buzeného plazmatu, Ramanovu spektroskopii a částečně techniky indukčně vázaného plazmatu. Výhody těchto technik, užívajících laser jako excitační zdroj, jsou zdůrazněny a následné užití těchto analytických technik bylo podrobně rozvedeno.

In 1957, protein rich in cysteine able to bind cadmium was isolated from horse kidney and named as metallothionein according to its structural properties. Further, this protein and metallothionein-like proteins have been found in tissues of other animal species, yeasts, fungi and plants. MT is as a potential cancer marker in the center of interest, and its properties, functions, and behavior under various conditions are intensively studied. Our protocol describes separation of two major mammalian isoforms of MT (MT-1 and MT-2) using capillary electrophoresis (CE) coupled with UV detector. This protocol enables separation of MT isoforms and studying of their basic behavior as well as their quantification with detection limit in units of ng per \iL. Sodium borate buffer (20 mM, pH 9.5) was optimized as a background electrolyte, and the separation was carried out in fused silica capillary with internal diameter of 75 um and electric field intensity of 350 V/cm. Optimal detection wavelength was 254 nm.