ELLSA based profiling of surface glycosylation in microorganisms reveals that ß-glucan rich yeasts' surfaces are selectively recognized with recombinant banana lectin.

The surface of microorganisms is covered with polysaccharide structures which are in immediate contact with receptor structures on host's cells and antibodies. The interaction between microorganisms and their host is dependent on surface glycosylation and in this study we have tested the interaction of plant lectins with different microorganisms. Enzyme-linked lectin sorbent assay - ELLSA was used to test the binding of recombinant Musa acuminata lectin - BL to 27 selected microorganisms and 7 other lectins were used for comparison: Soy bean agglutinin - SBA, Lens culinaris lectin - LCA, Wheat germ agglutinin - WGA, RCA - Ricinus communis agglutinin, Con A - from Canavalia ensiformis, Sambucus nigra agglutinin - SNA I and Maackia amurensis agglutinin - MAA.

Site-specific and dose-dependent effects of glucocorticoid receptor phosphorylation in yeast Saccharomyces cerevisiae.

The glucocorticoid receptor (GR) signal transduction and transcriptional regulation are efficiently recapitulated when GR is expressed in Saccharomyces cerevisiae. In this report we demonstrate that the in vivo GR phosphorylation pattern, hormone dependency and interdependency of phosphorylation events were similar in yeast and mammalian cells. GR phosphorylation at S246 exhibited inhibitory effect on S224 and S232 phosphorylation, suggesting the conservation of molecular mechanisms that control this interdependence between yeast and mammalian cells.

Acute and/or chronic stress models modulate CuZnSOD and MnSOD protein expression in rat liver.

Cellular protection against oxidative stress is afforded by the enzyme superoxide dismutase (SOD). In this study, the protein levels of copper-zinc SOD (CuZnSOD) in the cytosolic and nuclear fraction, manganese SOD (MnSOD) in the mitochondrial, and cytosolic fraction and cytochrome c (cyt c) in the liver of male rats exposed to 2 h of acute immobilization (IM) or Cold stress, 21 days chronic isolation or their combinations (chronic/acute stress) were examined. The serum corticosterone (CORT) level was measured, as an indicator of stress stimuli.

Neuroendocrine and oxidoreductive mechanisms of stress-induced cardiovascular diseases.

The review concerns a number of basic molecular pathways that play a crucial role in perception, transmission, and modulation of the stress signals, and mediate the adaptation of the vital processes in the cardiovascular system (CVS). These highly complex systems for intracellular transfer of information include stress hormones and their receptors, stress-activated phosphoprotein kinases, stress-activated heat shock proteins, and antioxidant enzymes maintaining oxidoreductive homeostasis of the CVS. Failure to compensate for the deleterious effects of stress may result in the development of different pathophysiological states of the CVS, such as ischemia, hypertension, atherosclerosis and infarction.

Regional differences in antioxidative response of rat brain after cranial irradiation.

In order to examine if differences in activity and inducibility of antioxidative enzymes in rat cerebral cortex and hippocampus are underlying their different sensitivity to radiation, we exposed four-day-old female Wistar rats to cranial radiation of 3 Gy of gamma-rays. After isolation of hippocampus and cortex 1 h or 24 h following exposure, activities of copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT) were measured and compared to unirradiated controls. MnSOD protein levels were determined by SDS-PAGE electrophoresis and Western blot analysis.

Alterations in hippocampal antioxidant enzyme activities and sympatho-adrenomedullary system of rats in response to different stress models.

The study deals with activity of three antioxidant enzymes, copper, zinc-superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT) in hippocampus of rats, following the exposure to single chronic (individual housing or forced swimming) and acute (immobilization or cold) stress, as well as to combined chronic/acute stress. In addition, plasma noradrenaline (NA) and adrenaline (A) concentrations were measured in the same stress conditions, because their autooxidation can add to the oxidative stress. We observed that i) long-term social isolation and repeated forced swimming had minor effects on plasma catecholamines, but in the long-term pretreated groups, acute stressors caused profound elevation NA and A levels, ii) chronic stressors activate antioxidant enzymes, iii) acute stressors decrease catalase activity, their effects on CuZnSOD appear to be stressor-dependent, whereas MnSOD is not affected by acute stressors, and iv) pre-exposure to chronic stress affects the antioxidant-related effects of acute stressors, but this effect depends to a large extent on the type of the chronic stressor.

The radioprotective activities of turpentine-induced inflammation and alpha2-macroglobulin: the effect of dexamethasone on the radioprotective efficacy of the inflammation.

This work was aimed at the radioprotective efficacy of turpentine oil (TO), alpha2-Macroglobulin (alpha2-M), Amifostine (Ami) and/or dexamethasone (Dex). These agents were administrated, alone or in combination, prior to irradiation of rats with 6.7 Gy (LD(50/30)).

Effects of age and dexamethasone treatment on glucocorticoid response element and activating protein-1 binding activity in rat brain.

The effect of dexamethasone (DEX) on glucocorticoid receptor (GR)-mediated gene expression was examined in the brain of young and aged rats. Electrophoretic mobility shift assays showed that DEX treatment led to an increase of glucocorticoid response element (GRE) binding activity in aged rats, whereas in young animals GRE binding activity was decreased. Western blot analysis and reverse transcriptase polymerase chain reaction confirmed that, in aged animals, the GR mRNA and the GR protein levels were increased on DEX treatment.

Ontogenetic profile of ecto-ATPase activity in rat hippocampal and caudate nucleus synaptic plasma membrane fractions.

An ontogenetic study of ecto-ATPase activity and the content of enzyme proteins was assessed in the caudate nucleus and hippocampal synaptic plasma membranes isolated from rats at various ages (15, 30, 90, 180 and 365 days). The ontogenetic profile revealed that the enzyme activities in both brain areas were the highest on day 30 and 365, while the ecto-ATPase protein abundance was the highest on day 15 after birth. Possible explanation for obtained ontogenetic profile and the discrepancy between activity and abundance may reside in the fact that ecto-ATPase during development could exert additional roles other than those related to metabolism of ATP.

The responses of rat liver glucocorticoid receptors and genes for tyrosine aminotransferase, alpha-2-macroglobulin and gamma-fibrinogen to adrenalectomy-, dexamethasone- and inflammation-induced changes in the levels of glucocorticoids and proinflammatory cytokines.

The responses of liver glucocorticoid receptor (GR) and genes coding for a glucocorticoid-inducible tyrosine aminotransferase (TAT) and two acute-phase proteins (APP) [alpha2-macroglobulin (alpha2-M) and gamma-fibrinogen (Fb)] to changes in glucocorticoid (GC) and proinflammatory (AP) cytokine contents have been examined in rats after single or combined treatments with turpentine oil, dexamethasone (Dex) and adrenalectomy. Activation of two APP genes in turpentine-induced inflammation was accompanied by an increase in the level of GR mRNA and a preferential translocation of GR-GC complexes to the nucleoplasm, while the expression of TAT remained unaltered. Dex alone caused a decrease in the levels of GR and Fb mRNAs, activation of TAT and alpha2-M genes, a decrease in the affinity of hormone binding sites and redistribution of translocated GR-Dex complexes within the nuclei.

The late effects of proton irradiation on cell growth, cell cycle arrest and apoptosis in a human melanoma cell line.

The aim of this work is the in vitro study of the late effects of single proton irradiation on HTB63 human melanoma cell growth, cell cycle and cell death. The experimental conditions were focused on analyzing the effects of irradiation on the periphery of tumour that can be, in clinical practice, close to critical organs. Confluent cell monolayers were irradiated with single doses ranging from 1 - 20 Gy, using proton beams having an energy of 22.

Binding of estradiol to synaptosomal mitochondria: physiological significance.

The subsynaptosomal distribution and specific binding of 17beta-estradiol in vitro to mitochondria isolated from presynaptic nerve endings of female rat brain were examined. 17Beta-estradiol is (i) distributed unequally in synaptosomes and mitochondria posses the highest capacity to bind estradiol with respect to the available amount of the hormone. (ii) Estradiol binds specifically to isolated synaptosomal mitochondria.

Role of antioxidant enzymes in radiosensitivity of human blood cells.

The marked variability in radiation response among individuals of the same age group prompted us to investigate the role of antioxidative enzyme activity. Micronuclei (MN) and enzyme assays were performed on blood samples of healthy male volunteers. The procedure consisted of micronucleus analysis and measurement of the superoxide dismutase (SOD) activity in harvested blood samples irradiated in vitro with 2 Gy gamma-rays and in unirradiated control samples for each individual.

Effect of steroid hormone deprivation on the expression of ecto-ATPase in distinct brain regions of female rats.

Abundant evidence indicates that ATP and adenosine act as neurotransmitters or co-transmitters, influencing nerve cell physiology in various ways. Therefore, regulation of ATP-metabolizing enzymes is essential for the normal development and function of neuronal tissue. In the present study we have examined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone deprivation on the activity and expression of synaptic membrane ecto-ATPase in three extrahypothalamic brain areas of female rats, primarily not associated with reproductive function.

Chromosome aberrations, micronuclei, and activity of superoxide dismutases in human lymphocytes after irradiation in vitro.

The goal of this study was to provide data on the dose-dependent production of dicentrics and micronuclei in human lymphocytes irradiated with 22.6 MeV protons and to estimate the possible contribution of intracellular superoxide dismutases (SOD) to the relative biological effectiveness (RBE) of protons. For the dose-response study, heparinized whole blood of a healthy volunteer was irradiated with protons and X-rays employing radiation doses of 0.

Glucocorticoid receptors in ageing rats.

The role of the glucocorticoid receptor (GR) in senescence was studied in rats of increasing age. Statistically significant changes in the number of GRs from rat liver were detected, whereas the affinity for the ligand triamcinolone acetonide (TA) did not change with increasing age, and was in the range of 1-2 nM. In all cases the number of receptors was lower in rats treated with hormone in vivo relative to untreated animals.

Identification and characterization of glucocorticoid receptors in B16 mouse melanoma cells.

Objective: To gain better insight into the role of glucocorticoids as modulators of cell growth, as well as to investigate the presence and characteristics of glucocorticoid receptors (GR) in mouse melanoma cells.

Methods: In two different B16 mouse melanoma cell clones (B16/F10 and B16/C3) the role of synthetic glucocorticoids (triamcinolone acetonide, TA) as cell growth modulators was investigated.

Results: The inhibitory effect of TA on B16/F10 cell growth after 8 days in culture was observed.

Adrenalectomy and dexamethasone treatment alter the patterns of basal and acute phase response-induced expression of acute phase protein genes in rat liver.

Hormonal requirements for full hepatic expression of alpha2-macroglobulin (alpha2M), alpha1-acid glycoprotein (AGP), haptoglobin (Hp) and gamma-fibrinogen (Fb) were assessed at the level of mRNA. Prior to exposure to turpentine-induced inflammation, rats were either depleted of glucocorticoids by adrenalectomy or supplemented with an excess of dexamethasone. Adrenalectomy alone did not affect the basal level of acute phase protein (APP) expression except for alpha2M mRNA, the level of which was enhanced.

Using yeast to study glucocorticoid receptor phosphorylation.

The glucocorticoid receptor (GR) is a phosphoprotein and a member of the steroid/thyroid receptor superfamily of ligand dependent transcription factors. When the glucocorticoid receptor is expressed in yeast (Saccharomyces cerevisiae), it is competent for signal transduction and transcriptional regulation. We have studied the glucocorticoid receptor phosphorylation in yeast and demonstrated that the receptor is phosphorylated in both the absence and presence of hormone, on serine and threonine residues.

Influence of pyridine and urea on the rat brain ATPase activity.

The neurotoxicity of pyridine and urea was investigated in respect to their ability to alter the activity of synaptosomal membrane Na+/K(+)-ATPase and Mg(2+)-ATPase. In vitro treatment with pyridine and urea stimulated Na+/K(+)-ATPase activity in a dose-dependent manner up to 40% and 60%, respectively. Mg(2+)-ATPase activity increased up to 40% after pyridine treatment, while urea had no effect at all.

Estradiol in vitro modulates Na+-dependent Ca2+ uptake by synaptic plasma membrane vesicles of rat brain regions.

Membrane vesicles loaded with [Na+], prepared from synaptosomal plasma membranes (SPM) of whole brains (WB), hippocampi (Hip) and caudate nuclei (NC) of female rats, were used to study Na+ -dependent Ca2+ transport across SPM vesicles under the influence of 17beta-estradiol (E2) in vitro. In concentrations near to physiologic, E2 significantly increased 45Ca2+ uptake by SPM vesicles from all the brain tissues investigated. The maximum increase was observed for WB (21%) and Hip (33%) at 10(-9) mol/l, and for NC (31%) at 5 x 10(-9) mol/l of E2.

Effects of estradiol benzoate and progesterone on superoxide dismutase activity in the rat liver.

Activities of superoxide dismutases MnSOD and CuZnSOD were measured in appropriate subcellular fractions prepared from livers of intact and long-term gonadectomized (GX) rats of both sexes, and of GX female and male rats injected sc with a single dose of 5 micrograms estradiol benzoate (EB) or 2 mg progesterone (P). In female livers, MnSOD activity did not vary significantly during the estrous cycle, declined after gonadectomy in comparison to proestrus, and was steady in GX females treated with EB or P. The activity of CuZnSOD was lowered at proestrus and elevated after removal of the ovaries in comparison to proestrus value.

Steroid receptors in nonmalignant and malignant kidney tissue of patients with endemic (Balkan) nephropathy.

The presence, affinity, binding capacity, structure and function of receptors for estrogen (ER), progesterone (PR) and glucocorticoid (GR) were investigated in 24 autologous pairs of control and neoplastic kidney tissues of patients with endemic (Balkan) nephropathy. In control tissue, all the three steroid receptors were absent in 20.8% and present in 25.