Immunomodulating effect of cyclophosphamide on cytotoxic activity of rat and mouse splenocytes

The goal of this work consisted in study of the immunomodulating action of the cytostatic drug cyclophosphamide (CP) on the natural cytotoxic activity of rat and mice splenocytes. The cytotoxicity of effector cells (EC) with respect to monolayer cell lines of the Zajdela rat hepatoma and the HTC rat hepatoma and of the MH-22a mouse hepatoma was determined with the aid of morphometric analysis. CP at a dose of 100 mg/kg 48 h after administration to animals has been shown to produce an immunomodulating effect on cytotoxicity of splenocytes—a suppressive one with respect to cell-targets (CT) of Zajdela hepatoma and an immunopotentiating one with respect to CT of HTC and MH-22 hepatomas. Possible mechanisms of the CP immunopotentiating action are discussed.     

Compromised root development constrains the establishment potential of native plants in unamended alkaline post-mining substrates

Plant and Soil - In water-limited areas, shrubs influence biological soil crust (biocrust) composition and diversity via soil microenvironment alterations and through modifying biotic interactions...     

Peroxide-Induced Damage to Plasminogen Molecules

Doklady Biochemistry and Biophysics - Plasminogen is a zymogenic form of plasmin, an enzyme that plays a fundamental role in the dissolution of fibrin clots as well as in many other physiological...     

Oxidative stress,nitric oxide,endothelial dysfunction and tinnitus

To assess whether pathogenic endothelial dysfunction is involved in acute idiopathic tinnitus we enrolled 44 patients and 25 healthy volunteers. In blood from the internal jugular vein and brachial vein we determined malonaldehyde, 4-hydroxynonenal, mieloperoxidase, glutathione peroxidase, nitric oxide, l-arginine and l-ornitine, thrombomodulin (TM) and von Willebrand factor (vWF) activity during tinnitus and asymptomatic period.

Higher plasma concentrations of oxidative markers and l-arginine, and lower nitric oxide and l-ornitine levels were observed in jugular blood of patients with tinnitus, there being a significant difference between brachial and jugular veins. TM and vWF activity were significantly higher in patients' jugular blood than in brachial blood.

Our results suggest oxidant, TM, vWF activity production are increased and nitric oxide production reduced in brain circulation reflux blood of patients with acute tinnitus. These conditions are able to cause a general cerebro-vascular endothelial dysfunction, which in turn induce a dysfunction of microcirculation in the inner ear.     

The KND olygopeptide as a putative endogenous prototype of Delta Sleep Inducing Peptide (DSIP). comparative study of biological properties

Biological properties of the known Delta Sleep-Inducing Peptide (DSIP, WAGGDASGE) were studied in vivo in comparison with those of a new DSIP-homologous peptide (WKGGNASGE — ([K ², N ⁵]DSIP, KND). This new peptide was recently discovered as the 324–332 fragment of the human lysine-specific histone demethylase 3B (EC 1.14.11, Swiss-Prot: Q7LBC6.1, 1761 a.a.) in the course of a computer search in available databases of proteins and nucleic acids. This demethylase belongs to the JmjC-domain-containing family of histone demethylases which are encoded by the JMJD1B gene and present in tissues of various mammals. These studies confirmed our preliminary conclusions on the functional similarity between the biological activities of DSIP and KND. The examined antioxidative, anticonvulsive, and behavioral effects of KND proved to be more pronounced than those of DSIP. The obtained results additionally sup-ported our hypothesis about KND being an endogenous prototype of a “real” DSIP.     

The competition between methyl viologen and monodehydroascorbate radical as electron acceptors in spinach thylakoids and intact chloroplasts

In spinach thylakoids prepared from intact chloroplasts by shocking in the presence of ascorbate to preserve the operation of ascorbate peroxidase, the rate of oxygen uptake with methyl viologen as acceptor decreased in response to the addition of H₂O₂. Such a decrease was not observed in the presence of KCN or when the thylakoids lost ascorbate peroxidase activity. Illumination of intact chloroplasts in the presence of H₂O₂ and methyl viologen showed an initial rate of oxygen exchange, which is intermediate between the initial rate of oxygen evolution in the presence of H₂O₂ alone and steady-state oxygen uptake in the presence of methyl viologen. The data showed that monodehydroascorbate radical generated in ascorbate peroxidase reaction could compete with methyl viologen for electrons supplied by the electron transport chain in both thylakoids and intact chloroplasts. During the illumination of intact chloroplasts the rate of oxygen uptake increased. The presence of nigericin swiftly led to steady-state oxygen uptake, and to a clear-cut 1:1 relationship between the electron transport rate estimated from fluorescence assay and the electron transport rate determined from oxygen uptake, taking the stoichiometry 1O₂:4e. The increase in oxygen uptake was attributed to the cessation of monodehydroascorbate radical generation brought about by consumption of intrachloroplast ascorbate in the peroxidase reactions, and the effects of nigericin were explained by acceleration of such consumption. The competition between methyl viologen and monodehydroascorbate radical in the intact chloroplasts was estimated under various conditions.     

DNA damage causes TP53-dependent coupling of self-renewal and senescence pathways in embryonal carcinoma cells

Comment on: Wu R, et al. Clin Cancer Res 2011; 17:7359–72