Additional value of tau protein measurement in the diagnosis of Creutzfeldt-Jakob disease.

Since the definite diagnosis of Creutzfeldt-Jakob disease (CJD) can currently only be provided by autopsy, there is a special need for fine diagnostic tools in live patients to achieve accurate diagnosis as early as possible. The aim of this study was to perform a preliminary retrospective analysis on the utility of the measurement of total Tau (tTau) and some other biomarkers from the cerebrospinal fluid (CSF) of patients with rapidly progressive dementia in the diagnostic work up of CJD. Beside the assessment of relevant clinical data and the findings of electroencephalography and brain magnetic resonance imaging, the presence of 14-3-3 protein and the levels of tTau were determined by Western blot technique and enzyme-linked immunosorbent assay from the CSF of 19 patients diagnosed with rapidly progressive dementia between the period of 2004-2017 at the Department of Neurology, University of Szeged. This preliminary study provided 100% sensitivity for 14-3-3, and interestingly, only 40% specificity to support the clinical diagnosis of CJD. Regarding tTau, the sensitivity values were calculated to be 100% or 83%, whereas the specificity values were 71% or 86%, depending on the applied cut-off levels. The poor specificity of 14-3-3 is not in line with literature data and may be the result of the small number of patients in the cohort with non-prion disease, predominantly consisting of disorders with considerable tissue damage, whereas tTau presented good sensitivity and specificity values. The combined application of these and novel chemical biomarkers may increase both sensitivity and specificity to a desired level.

Heavy metal accumulation and tolerance of energy grass (Elymus elongatus subsp. ponticus cv. Szarvasi-1) grown in hydroponic culture.

Phytoremediation is a plant based, cost effective technology to detoxify or stabilise contaminated soils. Fast growing, high biomass, perennial plants may be used not only in phytoremediation but also in energy production. Szarvasi-1 energy grass (Elymus elongatus subsp. ponticus cv. Szarvasi-1), a good candidate for this combined application, was grown in nutrient solution in order to assess its Cd, Cu, Ni, Pb and Zn accumulation and tolerance. Its shoot metal accumulation showed the order Pb < Ni < Cu ∼ Cd < Zn. In parallel with this, Pb and Ni had no or very little influence on the growth, dry matter content, chlorophyll concentration and transpiration of the plants. Cu and Cd treatment resulted in significant decreases in all these parameters that can be attributed to Fe plaque formation in the roots suggested by markedly increased Fe and Cu accumulation. This came together with decreased shoot and root Mn concentrations in both treatments while shoot Cu and Zn concentrations decreased under Cd and Cu exposure, respectively. Zn treatment had no effect or even slightly stimulated the plants. This may be due to a slight stimulation of Fe translocation and a very efficient detoxification mechanism. Based on the average 300 mg kg⁻¹ (dry mass) Zn concentration which is 0.03% of the shoot dry mass the variety is suggested to be classified as Zn accumulator.

Chelator-enhanced lead accumulation in Agropyron elongatum cv Szarvasi-1 in hydroponic culture.

Hydroponic culture was applied to compare the efficiency of K2EDTA and citrate in mobilizing Pb for accumulation in Agropyron elongatum cv. Szarvasi-1 and their effects on some physiological characteristics of the plants. The plants were grown in nutrient solutions containing 0, 10, and 100 microM Pb(NO3)2 combined with chelating agents added to the nutrient solutions after 21 days of growth, in 3 concentrations (0, 100, and 500 microM). The effects were measured after eight days. The energy grass proved to be greatly resistant to the treatments, as was reflected in the slight inhibition of growth, the resistance of the photosynthetic electron transport chain and the chlorophyll composition and the lack of change in the malone-dialdehyde content. Fundamental differences can be identified between the effects of EDTA and citrate. Citrate had only a little effect on the physiological parameters, which may be due to the strongly increasing lead accumulation with increasing concentration of Pb in the nutrient solution. Additionally, citrate ensured a higher biomass yield with higher shoot Pb accumulation compared to EDTA in almost all treatments. Concerning biomass reduction, 10 microM Pb applied together with K2EDTA has the most deleterious effects on energy grass. The effects correlated with the concentration of EDTA.

Arsenic speciation in xylem sap of cucumber (Cucumis sativus L.).

Flow injection analysis (FIA) and high-performance liquid chromatography double-focusing sector field inductively coupled plasma mass spectrometry (HPLC-DF-ICP-MS) were used for total arsenic determination and arsenic speciation of xylem sap of cucumber plants (Cucumis sativus L.) grown in hydroponics containing 2 micromol dm(-3) arsenate or arsenite, respectively. Arsenite [As(III)], arsenate [As(V)] and dimethylarsinic acid (DMA) were identified in the sap of the plants. Arsenite was the predominant arsenic species in the xylem saps regardless of the type of arsenic treatment, and the following concentration order was determined: As(III) > As(V) > DMA. The amount of total As, calculated taking into consideration the mass of xylem sap collected, was almost equal for both treatments. Arsenite was taken up more easily by cucumber than arsenate. Partial oxidation of arsenite to arsenate (<10% in 48 h) was observed in the case of arsenite-containing nutrient solutions, which may explain the detection of arsenate in the saps of plants treated with arsenite.