Preparation of conjugated antigens based on zearalenone carboxymethyloxime and their use in enzyme immunoassay

Zearalenone-6′-carboxymethyloxime was synthesized, and its conjugates to albumins and gelatin were prepared. Polyclonal rabbit antibodies against the conjugate with bovine serum albumin were shown to be highly specific to zearalenone and to have a lower cross-reactivity toward its structural analogues (a-zearalenol, 28%; ß-zearalenol, 6%; zearalanone, 12%; and α-zearalanol, 5%). The sensitivity of enzyme immunoassay with immobilized gelatin-based conjugates for determination of zearalenone in solution was 1 ng/ml, and this allowed us to determine this substance in feed at a threshold concentration of 200 μg/kg.     

A survey on the occurrence of citrinin in feeds and their ingredients in Russia

More than 1700 samples of forage grain, sunflower and soy-bean oil-seed meal and cakes, gluten, and compounded feeds were analyzed for citrinin by indirect ELISA with a minimum detectable level of 10 ppb. Out of 829 compounded feeds (rations and concentrates) 8.8 per cent samples were positive and the amount of citrinin ranged between 12 and 182 ppb. Only 4.5% of wheat and 3.6% of barley contained citrinin at 50–998 ppb. 1.9% of maize grain samples were positive at levels of 218–953 ppb. Among the other ingredients the highest incidence (28.9%) at the levels of 14–397 ppb was found for sunflower oil-seed meal and cakes. Three positive cases of 148 processed soy-bean samples contained citrinin in a range of 14–30 ppb. Presented at the IV Russian Congress on Medical Mycology, Moscow, Russia, March 2006     

Isolation of steroid-binding proteins on new affinity adsorbents]

Steroid-binding proteins of human blood are extracted and investigated on corticosteroid-hydrazide-oxypropyl-adsorbents by the affinity chromatography. The role of structural changes in the matrix-spacer-ligand system for different types of adsorbents is studied as well as a dependence of sorption on pH and salt environment. A dependence of the protein sorption on the isolated hydrazide groups is revealed. It is shown that hydrocortisone displays the highest binding activity to the protein pool in the affinity electroimmunoassay while the substance S-Reichstein and its 16-alpha-methyl analog--the least one.     

Anticancer Properties of Flagellate Protozoan Trypanosoma cruziChagas, 1909

The anticancer activity of Trypanosoma cruzihas been confirmed by the example of seven strains. Five virulent strains induced the infection, which inhibited sarcoma-180 growth 1.5–22.0 times. The parasites featured tumortropism; i.e., they successfully developed in cancer cells and even preferred them to normal cells. This taxis-based phenomenon was particularly pronounced at cocultivation of the normal and cancer cells. Cultures of the seven (avirulent and virulent) strains can produce an anticancer agent that selectively damages human cancer cells in vitro. The long-term anticancer effect of T. cruzior preparations from it, as well as possible its cancer preventing effect, has been demonstrated. Three problems are discussed on the basis of the obtained and recently published data: (1) the mechanism of T. cruzianticancer effect; (2) the nature of the anticancer agent; and (3) the distribution of the considered phenomenon among trypanosomatides. The anticancer activity of T. cruzimay be due to a combination of surface cellular antigens and an inhibiting or lysing factor.     

Effect of intracellular cyclic AMP injection on calcium current in identifiedHelix pomatia neurons

The effect of intracellular injection of cyclic AMP (cAMP) and extracellular application of theophylline on the inward calcium current was investigated in neurons RPa3 and LPa3 ofHelix pomatia. Iontophoretic injection of cyclic AMP (current 10–35 nA, duration about 1 min) led to a decrease in amplitude of the calcium current to a new stationary level, which depended on the injection current. After the end of injection the calcium current was restored to its initial level. Current-voltage characteristic curves of the calcium current were not shifted along the voltage axis by cAMP injection, indicating that the reduction in this current was connected with a change in maximal calcium conductance. An increase in the frequency of depolarizing shifts from 0.1 to 0.5 Hz caused a decrease in the calcium current but did not affect the time course of the decrease in calcium current in response to injection of cAMP or the time course of its recovery after the end of injection. Theophylline an inhibitor of cyclic nucleotide phosphodiesterase, in a concentration of 1 mM in the external solution, lowered the amplitude of the calcium current by 50–75% of its initial value. In 40% of neurons, abolition of the action of theophylline by rinsing was incomplete, but in the rest the effect of theophylline was irreversible. It is postulated on the basis of the results that cytoplasmic compounds take part in regulation of the calcium current of molluscan neurons. The possible physiological role of this process is discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 14, No. 3, pp. 290–297, May–June, 1982.     

New isoform HvNHX3 of vacuolar Na<Superscript>+</Superscript>/H<Superscript>+</Superscript>-antiporter in barley: Expression and immunolocalization

The gene HvNHX3 encoding a new isoform of vacuolar Na⁺/H⁺-antiporter was identified in barley. This gene is expressed in roots and leaves of barley seedlings, and it encodes a protein consisting of 541 amino acid residues with pre-dicted molecular weight 59.7 kDa. It was found that by its amino acid sequence HvNHX3 is closest to the Na⁺/H⁺-antiporter HbNHX1 of wild type from Hordeum brevisibulatum that grows on salt-marsh (solonchak) soils (95% homology). The expression of HvNHX3 during salt stress is increased several-fold in roots and leaves of barley seedlings. At the same time, the amount of HvNHX3 protein in roots does not change, but in leaves it increases significantly. It was shown using HvNHX3 immunolocalization in roots that this protein is present in all tissues, but in control plants it was clustered and in experimental plants after salt stress it was visualized as small granules. It has been proposed that HvNHX3 is converted into active form during declusterization. The conversion of HvNHX3 into its active form along with its quantitative increase in leaves during salt stress activates Na⁺/H⁺-exchange across the vacuolar membrane and Na⁺ release from cytoplasm, and, as a consequence, an increase of salt stress tolerance.     

Products of spontaneous conjugation of aflatoxins with bovine serum albumin: immunochemical properties

Products of spontaneous conjugation of aflatoxins B1, G1, and G2 with bovine serum albumin (BSA) were shown to interact with antibodies against aflatoxins. Solid-phase BSA conjugates inhibited the binding of aflatoxins by anti-aflatoxin antibodies. Antisera against BSA-B1, BSA-G1, and BSA-G2 were obtained and their specificity, determined. The mechanisms of spontaneous binding of aflatoxins by proteins are discussed.     

Flora Europaea Notulae Systematicae ad Floram Europaeam spectantes No. 20 Corrigenda et Addenda

Following the publication of the last of the series of Flora Europaea Notulae, No. 20 in the Botanical Journal of the Linnean Society , 76: 297–384 (1978), a number of additions or alterations have been drawn to our attention. These are published in continuation.