bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytostatic Activity of Some Phenolic Acids of Scrophularia frutescens L. var. frutescens
Authors: Garcia M. D. , Ahumada M. C. , Saenz M. T.
Published: August 2018

The cytostatic activity of seven phenolic acids: coumaric, caffeic, ferulic, gentisic, protocatechuic, syringic and isovanillic acid previously isolated from Scrophularia frutescens has been evaluated against Hep -2 cells (de­rived from a human epidermoid carcinoma of the lar­ynx) and McCoy cells (derived from the synovial fluid in the knee joint of a patient suffering from degenerative arthritis). The compounds belonging to the cinnamic group present the highest activity.
Gas Exchange Characteristics in Leaves of the Euphorbiacea Aleurites montana as Consequence of Growth under 700 ppm CO2 in Air A Study on Photosynthesis and Photorespiration in the Chinese Tung-Oil Tree
Authors: He P. , Bader K. P. , Radunz A. , Kahmann U. , Ruppel G. H. , Schmid G. H.
Published: August 2018

Three months old plants of the Chinese tung-oil tree Aleurites montana (Euphorbiaceae) were cultivated for 4 months in air containing 700 ppm CO2. These plants, which grow substantially better in the CO2-enriched atmosphere, were analyzed by mass spectrometry for photosynthesis and photorespiration together with control plants grown all the time in normal (350 ppm CO2) air. Thereafter part of the plants was subjected for two weeks to 0.3 ppm SO2 in the atmosphere and again analyzed for photosynthesis and photorespiration. Aleurites montana exhibits a strongly CO2-dependent photosynthesis which partially explains the observed stimulatory effect of 700 ppm CO2 on growth of the plant. In control plants grown in normal air, photorespiration measured simultaneously with photosynthesis via the uptake of l80 2 in the light, is much lower than in C3-plants like tobacco (H e et al., 1995, Z. Naturforsch. 50c, 781-788 ). In Aleurites grown in 700 ppm CO2, however, photorespiration is completely absent in contrast to tobacco when grown under 700 ppm CO2. In tobacco, photorespiration is not inhibited to the extent of the in vitro experiments in which plants grown at 350 ppm CO2 are measured under the increased CO2 content of 700 ppm. Gas exchange measurements carried out by mass spectrometry show that the ratio of O2 evolved to CO2 fixed is about 0.5. Apparently, part of the CO2 fixed is channelled into a metabolic path without concomitant O2-evolution. Although the plant has no succulent appearance (its leaves somehow resemble maple leaves) apparently a Crassulacean type metabolism is performed. When Aleurites plants grown all the time in normal air with 350 ppm, are exposed for two weeks to 0.3 ppm SO2 the treatment completely inhibits this CO2-fixing portion which is tentatively attributed to a Crassulacean type of metabolism. This is demonstrated by a normal C3-type ratio O2 evolved /CO2 fixed of 1. When Aleurites plants, grown for 4 months in a CO2-enriched atmosphere of 700 ppm CO2, are subjected for two weeks to 0.3 ppm SO2, the features of control plants show up again. When these plants are tested under 350 ppm CO2 the Crassulacean type CO2-fixation apparently is not inhibited by SO2. Photorespiration, although low, is present in the same activity as in the controls. Seemingly, an increased level of CO2 in air tends to alleviate the impact of the SO2 at least in the Chinese tung-oil tree.
ESR Study of the Liposome Membrane Physical Parameters in the Heating-Cooling Cycles
Authors: Podolak Marian , Mana Dariusz , Przestalski Stanislaw
Published: August 2018

Changes of dynamic and structural parameters of egg yolk lecithin (EYL) liposome mem­branes in the heating-cooling cycles have been studied using the E S R spin probe method. The investigations were conducted in the range of temperatures from -18 °C to +60 °C. It has been found that in the range of temperatures -15 °C to +45 °C in both the heating and the cooling run the spectroscopic parameters changed practically along the same curve (re­versible changes). However, after exceeding this range of temperatures one of the parameters (partition coefficient of the spin probe 2,2,6,6 -tetramethylpiperidine -1-oxyl; TEMPO) changed along a closed curve, showing the phenomenon of thermal hysteresis. In the heating process the TEMPO content in liposome membranes was smaller than this in the cooling process. We assume that during the heating, the lipid molecules of the outer liposome layers dissolve in the aqueous medium. In the cooling process they can aggregate and form new liposomes, what in turn increases the surface of liposome membranes, accessible for the TEMPO probe (active surface).
Chemical Composition of Egyptian Propolis
Authors: Christov R. , Bankova V. , Hegazi A. , Hady F. Abd El , Popov S.
Published: August 2018

A sample from Egyptian propolis was investigated by TLC and GC/MS. 39 compounds were identified, 8 being new for propolis. Partial structures of four new esters of caffeic acid have been proposed.
Inhibition by Salix-Extracts and PhytodolorR of Copper-Catalyzed Oxidative Destructions
Authors: Rohnert Ute , Koske Dagmar , Schneider Werner , Elstner Erich F.
Published: August 2018

Oxidation of low density lipoprotein (LDL) by copper ions is strongly inhibited by dif­ ferent aqueous extracts (Salix spec (SE); Fraxinus-Solidago-Populus (PhytodolorR)(PD)) in a concentration range between 4 and 7 μg/ml. 10 to 50 μᴍ salicylic acid (SA) stimulate LDL-oxidation whereas higher concentrations (10 to 500 μᴍ) show no effect. Likewise ethene release from 2-keto-4-methylthiobutyrate (KMB) is strongly inhibited by the above extracts in a reaction driven by dihydroxyfumarate (DHF) in the presence of copper ions. This system may represent som e features of the diabetic situation where DHF as an endiole may stand for certain Amadori products. In order to find out whether the inhibitory effects are due to copper chelation we tested the copper-dependent conversion of photodynamic ethane release from a-linolenic acid into ethene formation. Copper chelation is apparently only partially involved in inhibition of copper-dependent oxidations and only at a certain concentration of extracts from Salix spec (SE) or extracts from Fraxinus-Solidago-Populus (Phyto-dolorR)(PD).
Verticillium rexianum (SACC.) SACC., a New Producer of Monacolin K
Authors: Wagner Christian , Sterner Olov , Anke Heidrun
Published: August 2018

From the broth of submerged cultures of Verticillium rexianum (teleomorph: Nectriopsis exigua), a mycophilic fungus growing on myxomycetes, monacolin K was iso­lated as a weak inhibitor of pectate lyase. Monacolin K is the first secondary metabolite described from V. rexianum.
In vitro Influence of Phenylalanine on Acetylcholinesterase Activity and DNA
Authors: Schulpis Kleopatra H. , Karikas George A. , Tjamouranis Joana
Published: August 2018

Acetylcholinesterase (AChE) is a significant compo­nent of the membrane contributing to the permeability changes during synaptic transmission and conduction. Phenylketonuria is a group of metabolic disorders in which phenylalanine (Phe) is highly elevated in blood (up to 0 .1 ᴍ) resulting in*mental retardation etc. AChE activity was measured spectrophotometrically after incu­ bation with various Phe concentrations. Phe interaction with DNA was evaluated with an established HPLC method. Phe was found to inhibit AChE almost 40% , at a concentration of 5 mᴍ, whereas a 62.5% DNA peak exclusion (molecular interaction) was observed when Phe was incubated with DNA at a concentration of 3 mᴍ. In addition the ratio of DNA: Phe determined the potency of the observed molecular effect.
Carbazole Antibiotics Synthesis in a Streptomyces tendae Bald Mutant, Created by Acriflavine Treatment
Authors: Grammel Hartmut , Wolf Heinz , Gilles Ernst-Dieter , Huth Felix , Laatsch Hartmut
Published: August 2018

Acriflavine treatment on Streptomyces tendae generated a bald mutant (bid-1) with an altered antibiotic pattern. The parental strain produced nikkomycins and juglomycins, whereas the mutant bid-1 was only capable of juglomycin synthesis. The existence of a mutant defective in morphogenesis and in nikkomycin biosynthesis suggests a common regulation of these processes. An interesting finding of this study is that mutant bld-1 produced two carbazole derivatives, hitherto never seen in cultures of the parental strain. It seems likely that the DNA intercalating dye acriflavine, by mutagenesis, had activated cryptic genes which are involved in carbazole synthesis. The two carbazole derivatives were identified as the neuronal cell protecting compounds CS-79B and carquinostatin A, recently isolated from a wild-type of S. exfoliatus. We found that both substances showed antibacterial activity.
Biochemical Parameters as Biomarkers for the Early Recognition of Environmental Pollution in Scots Pine Trees. I. Phenolic Compounds
Authors: Hartling S. , Schulz H.
Published: August 2018

Pinus sylvestrish., Catechin, Ferulic Acid, p-Coumaric Acid, Picein Within a series of regular projects investigating the suitability of biochemical parameters as biomarkers for the early recognition of environmental pollution, the levels of selected phenolic compounds were determined in Scots pine needles (Pinus sylvestris L.) from young and adult trees at three field sites with different SO2 pollution (Rösa>Taura>Neuglobsow). Young trees showed no differences in the levels of soluble phenolics in case of increasing loads of SO2, whereas the concentration of the soluble phenolic component catechin in previous needles of adult trees altered significantly. In current year’ needles, differences were only found in the presence of high SO2 deposition. In contrast to catechin, picein and total phenolics remained unaffected. The concentration of catechin in the previous year’s needles of adult trees correlated positively with needle necroses.

The phenolic components of the cell walls of pine needles were also analysed. The main phenolic compounds were identified as p-coumaric acid and ferulic acid. Differences in the levels of p-coumaric acid were detected in the needles of adult trees between the three sites, with the highest levels being measured at the site with the lowest pollution (Neuglobsow). However, changes in the p-coumaric acid content in young trees were low. No site-related differences were found regarding ferulic acid in adult and young pines. The findings are discussed and compared with data reported in the literature.
Non-Uniform Triple Helical Structure in Chick Skin Type I Collagen on Thermal Denaturation: Raman Spectroscopic Study
Authors: Renugopalakrishnan V. , Carreira L. A. , Collette T. W. , Dobbs J. C. , Chandraksasan G. , Lord R.C.
Published: August 2018

The individual chains in the triple helix of collagen occur in a conformation related to polyproline II because of the presence of large number of imino peptide bonds. However, these residues are not evenly distributed in the collagen molecule which also contains many non-imino residues. These non-imino regions of collagen may be expected to show preference for other than triple helical conformations. The appearance of several Raman bands in solution phase at 65 °C raises the possibility of non-uniform triple helical structure in collagen. Raman spectroscopic studies on collagen in the solid state and in solution at a temperature greater than its denaturation temperature, reported here suggest that denatured collagen may exhibit an ensemble of conformational states with yet unknown implications to the biochemical interactions of this important protein component of connective tissues.
Solutions for the Binding Problem
Authors: Roelfsema Pieter R.
Published: August 2018

Visual cortical neurons are broadly tuned to one or a few feature dimensions, like color and motion. This is advantageous because broadly tuned neurons can contribute to the repre­sentation of many visual scenes. However, if there are multiple objects in a visual scene, the cortex is at risk to combine features of different objects as if they belong to a single object. The term “binding problem” was introduced to refer to the difficulties that may occur in sorting out those responses that are evoked by a single perceptual object. The present article reviews proposals suggesting that the binding problem is solved by labelling an assembly of neurons that is responsive to a single perceptual obejct. Evidence is reviewed in favor of two possible assembly-labels: rate enhancement due to visual attention and neuronal synchrony. Assembly-labels should be spread through the cortical network to all neurons that have to participate in an assembly The present article tries to shed light on the mechanisms that subserve such a selective spread of assembly labels. Moreover, it is suggested that assembly labels may fulfill an equivalent role in the motor system, since binding problems can also occur during the generation of useful patterns of motor activity.
Networks of Gene Regulation, Neural Development and the Evolution of General Capabilities, Such as Human Empathy
Authors: Gierer Alfred
Published: August 2018

Gene Regulation, Brain Evolution, Neural Network, Empathy, Evolution of Altruism A network of gene regulation organized in a hierarchical and combinatorial manner is crucially involved in the development of the neural network, and has to be considered one of the main substrates of genetic change in its evolution. Though qualitative features may emerge by way of the accumulation of rather unspecific quantitative changes, it is reasonable to assume that at least in some cases specific combinations of regulatory parts of the genome initiated new directions of evolution, leading to novel capabilities of the brain. These notions are applied, in this paper, to the evolution of the capability of cognition-based human empa­thy. It is suggested that it has evolved as a secondary effect of the evolution of strategic thought. Development of strategies depends on abstract representations of one’s own pos­sible future states in one’s own brain to allow assessment of their emotional desirability, but also on the representation and emotional evaluation of possible states of others, allowing anticipation of their behaviour. This is best achieved if representations of others are con­nected to one’s own emotional centres in a manner similar to self-representations. For this reason, the evolution of the human brain is assumed to have established representations with such linkages. No group selection is involved, because the quality of strategic thought affects the fitness of the individual. A secondary effect of this linkage is that both the actual states and the future perspectives of others elicit vicarious emotions, which may contribute to the motivations of altruistic behaviour.
Conformational Studies of the Emp-AKH Peptide Using Molecular and Langevin Dynamics Methods
Authors: Zubrzycki Igor Zbigniew
Published: August 2018

The secondary structure of the member of the AKH/RPCH family has been studied by Molecular Dynamics and Langevin Dynamics methods. Molecular dynamics simulation were performed in vacuum, model aqueous solution and simulated membrane. Langevin dynamics simulation was performed using the friction factor γ equal to 2 ps-1. Molecular dynamics as well as Langevin Dynamics simulation were conducted at 300 K. All minimum energy conformers have similar backbone structure characterised by the turn consisted out of 3 amino acids, Thr, Pro and Asn7. Structures obtained from Molecular Dynamics simulation are characterised by the lack of hydrogen bonds whereas the structure obtained form Langevin Dynamics simulation is stabilised by the web of hydrogen bonds.
Epicuticular Wax Compositions of Predominant Conifers of Western North America
Authors: Oros Daniel R. , Standley Laurel J. , Chen Xiaojing , Simoneit Bernd R.T.
Published: August 2018

The compositions of epicuticular waxes from conifers constituting the predom inant species of western North America were determined by GC and GC-MS. The primary components identified include alkanes, fatty acids, fatty alcohols, aldehydes, ketones, phytosterols, triterpenoids and wax esters. Average chain lengths (ACL) for alkanes in Oregon conifers decreased with increasing distance away from the Coastal range which suggests an adaptation by conifers to humid climate conditions. Differences in the chemical compositions make this information useful for chemotaxonomic purposes, for identifying natural organic aerosol input sources to the atmosphere, for comparison with the tracers in smoke emissions from burning of these biomass fuels, and for monitoring in assessment of global climate change
Ouabain-Insensitive Na+-ATPase Activity in Trypanosoma cruzi Epimastigotes
Authors: Caruso-Neves Celso , Einicker-Lamas Marcelo , Chagas Carlos , Oliveira Mecia Maria , Vieyra Adalberto , Lopes Aníbal Gil
Published: August 2018

In the present paper, the presence of a ouabain-insensitive Na+-stimulated, Mg2+-dependent ATPase activity in T. cruzi epimastigotes CL14 clone and Y strain was investigated. The increase in Na+ concentration (from 5 to 170 mᴍ), in the presence of 2 mᴍ ouabain, increases the ATPase activity in a saturable manner along a rectangular hyperbola. The was 18.0 ± 1.0 and 21.1 ± 1.1 nmoles Pi x mg-1 x min-1 and the half-activation value (K50) for Na+ was 34.3 ± 5.8 mᴍ and 37.7 ± 5.3 in CL14 clone and in Y strain, respectively. The Na+-stimulated ATPase activity was inhibited by 5-[aminosulfonyl]-4-chloro-2-[(2-furanylmethyl)-amino] benzoic acid (furosemide) in a dose-dependent manner. The half-inhibition value (I50) was 0.22 ± 0.03 and 0.24 ± 0.07 mᴍ, and the Hill number (n) was 0.99 ± 0.2 and 2.16 ± 0.29 for CL14 clone and Y strain, respectively. These data indicate that both cell types express the ouabain-insensitive Na+-ATPase activity, which might be considered the bio­chemical expression of the second Na+ pump
Expression of Functionally P-Glycoprotein in MA104 Kidney Cells
Authors: Capella Márcia A. M. , Morales Marcelo Marcos , Orind Monique , Rumjanek Vivian M. , Lopes Aníbal Gil
Published: August 2018

Rhesus monkey kidney MA104 cells are a polarized epithelium with some unusual characteristics, including a resistance to ouabain, although their Na+-K+-ATPase has normal affinity with this drug. This work suggests that MA104 cells have high expression of functionally P-glycoprotein in their membranes. This was established using four complementary methods to investigate the expression and function of P-glycoprotein in these cells. MA104 cells were strongly resistant to vincristine, which could be reversed by three know n P-glycoprotein modulators; verapamil, cyclosporin A and trifluoperazine. In addition, MA104 cells accumulate little rhodamine 123, and the incubation with verapamil increased this accumulation. The mdr1-mRNA was detected by reverse transcription-polymerase chain reaction and a subcloned 283-bp product was identified. Its nucleotide sequence was compared with the related region of hum an mdr1, showing a high identity (96% ) between the two sequences. The expression of P-glycoprotein in the cell membrane was observed by Western blot and immunofluorescence. The results taken together suggest that MA104 cells intrinsically have a high expression of functionally P-glycoprotein in their membranes
Polyphenols in Stachys and Betonica Species (Lamiaceae)
Authors: Bankova Vassya , Koeva-Todorovska Jordanka , Stambolijska Tatyana , Ignatova-Groceva Maria-Desislava , Todorova Daniela , Popov Simeon
Published: August 2018

Above-ground parts and roots from four Stachys species (S. germanica L., S. sylvatica L. and the Balkan endemics S. thracica Dav. and S. plumosa Griseb.) as well as o f three Betonica species (B. officinalis L. and the Balkan endemics B. bulgarica Deg. et Neic. and B. scardica Griseb.) were screened for phenols (phenylethanoid glycosides, flavonoid glycosides and the phenolic diterpene betolide). Three phenylethanoid glycosides, a flavonoid glycoside and the phenolic diterpene betolide were isolated and identified, most of them for the first time in the investigated species. The results obtained support the view that Stachys and Betonica are well separated genera.
Effect of Dissolved Oxygen Concentration on Superoxide Dismutase Production by Humicola lutea Cells
Authors: Pashova Svetlana B. , Slokoska Ludmila S. , Dolashka-Angelova Pavlina A. , Vassilev Spassen V. , Sheremetska Pravda D. , Angelova Maria B.
Published: August 2018

Cultures of the fungal strain Humicola lutea 110 were grown in a 3-l bioreactor. Effects of dissolved oxygen concentration (DO) on cell growth, intracellular protein content and antioxidant enzyme activities (SOD and catalase) were investigated. Controlling DO from 20 to 60% lead to: (I). The lethal phase of growth was reached faster; (ii) strong reduction of the intracellular protein content, and (iii) increase of antioxidant enzyme activities. The most efficient SOD biosynthesis was achieved at the 1st maximum of activity in the culture grown under DO uncontrolled conditions.
Bleomycin - Induced DNA Damage and DNA Repair in Chicken Embryo Cells as Compared to X-Irradiation
Authors: Tempel Karlheinz , Kortenbeutel Hannelore , Zallinger Christina von
Published: August 2018

Following in vitro- and in ovo-exposure of chicken embryo cells, the level of bleomycin (BM) - induced damage was evaluated by using DNA synthesis, nucleoid sedimentation (SED), and viscometry of alkaline cell lysates (VISC). This damage was compared to Xirradiation, using 5.9-378 nM BM in vitro, 1.5-116 μg BM/egg in ovo, and 2-32 Gy, respectively, in vitro as well as in ovo. With respect to BM. the most notable result is the increase in DNA synthesis and VISC at the lowest concentrations of the drug. A decrease in both parameters was observed at high BM concentrations and following exposure to X-rays, concomitantly with an increase in SED. Regarding the radiomimetic drug BM and X-rays, different modes of DNA damage and DNA repair are suggested by previous investigations and the present results. Therefore, further evidence is presented, that the chicken embryo can act as a simple, rapid and inexpensive test system to characterize the biological effects of many nucleo- and/or cytotoxic agents.
Contribution of a Metal-Peroxide Adduct to Neurodegeneration Is Due to Its Oxidative Protease Activity
Authors: Nishida Yuzo , Nishino Satoshi
Published: August 2018

Many hypotheses have been developed to explain aging and age-related neurodegenerative disorders; one of the most compelling is the role of oxidative stress to induce changes in protease activity in brains of patients of Alzheimer’s disease and prion disease. At the moment however, there is no clear answer how protein degradation may be achieved in the brain. We have observed that several metal compounds can degrade proteins in the presence of hydrogen peroxide, and elucidated the reaction scheme based on the new theoretical point for the reactivity of a metal-peroxide adduct with η1-coordination mode. In this article we would like to point out the importance of a copper(II)-peroxide adduct to promote neurodegenerative diseases such as prion disease and amyotrophic lateral sclerosis through its oxidative protease function.
An Exceptionally Large Pyoverdin from a Pseudomonas Strain Collected in Thailand+
Authors: Ruangviryachai Chalerm , Barelmann Insa , Fuchs Regine , Budzikiewicz Herbert
Published: August 2018

From a Pseudomonas strain obtained from a soil sample collected in Thailand a pyoverdin was obtained containing twelve amino acids in its peptide chain. The structure elucidation is described.
Isoangoroside C, a Phenylpropanoid Glycoside from Scrophularia scorodonia Roots
Authors: Santos Javier de , Lanza Ana M. Díaz , Fernández Lidia , Rumbero Angel
Published: August 2018

A new phenylpropanoid glycoside isoangoroside C was isolated from the roots of Scrophularia scorodonia. Its structure was determined on the basis of spectral data as: 3-hydroxy- 4-methoxy-β-phenylethoxy-O-α-ʟ-arabinopyranosyl-(1→6)α ʟ-rhamnopyranosyl-(l→3)-4-O- Z-feruloyl-β-ᴅ -glucopyranoside. Additionally, one known phenylpropanoid, angoroside C, and five known iridoid glycosides, harpagoside, bartsioside, 8-O-acetyl-harpagide, aucuboside and harpagide were isolated and identified.
Oxidative Metabolism of Ambrox and Sclareolide by Botrytis cinerea
Authors: Farooq Afgan , Tahara Satoshi
Published: August 2018

Ambrox (1), a perfumery diterpene, was oxidatively metabolised by a plant pathogenic fungus Botrytis cinerea in a xenobiotic fashion to afford a major product, i.e., 1β-hydroxy-8- epiambrox (13) (60% ) along with three minor metabolites 3β-hydroxyambrox (2), sclareolide (5) and 3β-hydroxysclareolide (7). Sclareolide (5), a cytotoxic diterpenoidal lactone was fermented with the same fungus to yield 3β-hydroxysclareolide (7) (59% ) as a major metabolite together with two minor metabolites characterised as 1-ketosclareolide (15), and 3β,14-dihydroxysclareolide (16).
Metal Binding to Pseudomonas aeruginosa Azurin: a Kinetic Investigation
Authors: Naro Fabio , Tordi Maria G. , Giacometti Giorgio M. , Tomei Francesco , Timperio Anna M. , Zolla Lello
Published: August 2018

The interaction between azurin from Pseudomonas aeruginosa and Ag(I), Cu(II), Hg(II), was investigated as a function of protein state, i.e. apo-, reduced and oxidised azurin. Two different metal binding sites, characterized by two different spectroscopic absorbancies, were detected: one is accessible to Ag(I) and Cu(II) but not to Hg(II); the other one binds Ag(I) and Hg(II) but not copper. When added in stoichiometric amount, Ag(I) shows high affinity for the redox center of apo-azurin, to which it probably binds by the -SH group of Cys112; it can displace Cu(I) from reducedazurin, while it does not bind to the redox center of oxidizedazurin. Kinetic experiments show that Ag(I) binding to the reducedform is four times faster than binding to the apo-form. This result suggests that metal binding requires a conformational rearrangement of the active site of the azurin.

Interaction of A g(I) or Hg(II) ions to the second metal binding site, induces typical changes of UV spectrum and quenching of fluorescence emission.
Photoinactivation and Protection of Glycolate Oxidase in vitro and in Leaves
Authors: Schäfer Lutz , Feierabend Jürgen
Published: August 2018

Glycolate oxidase that was partially purified from pea leaves was inactivated in vitro by blue light in the presence of FMN. Inactivation was greatly retarded in the absence of O2. Under aerobic conditions H2O2 was formed. The presence of catalase, GSH or dithiothreitol protected glycolate oxidase against photoinactivation. Less efficient protection was provided by ascorbate, histidine, tryptophan or EDTA. The presence of superoxide dismutase or of hydroxyl radical scavengers had no, or only minor, effects. Glutathione suppressed H2O2 accumulation and was oxidized in the presence of glycolate oxidase in blue light. Glycolate oxidase was also inactivated in the presence of a superoxide-generating system or by H2O2 in darkness. In intact leaves photoinactivation of glycolate oxidase was not observed. However, when catalase was inactivated by the application of 3-amino-1,2,4-triazole or depleted by prolonged exposure to cycloheximide a strong photoinactivation of glycolate oxidase was also seen in leaves. In vivo blue and red light were similarly effective. Furthermore, glycolate oxidase was photoinactivated in leaves when the endogenous GSH was depleted by the application of buthionine sulfoximine. Both catalase and antioxidants, in particular GSH, appear to be essential for the protection of glycolate oxidase in the peroxisomes in vivo.
Effects of Naturally Occurring Polyols and Urea on Mitochondrial F0F1ATPase
Authors: Lemos Adriana dos Passos , Peres-Sampaio Carlos E. , Guimarães-Motta Horácio , Silva Jerson L. , Meyer-Fernandes José R.
Published: August 2018

We show that urea inhibits the ATPase activity of MgATP submitochondrial particles (MgATP-SMP) with Ki = 0.7 м, probably as a result of direct interaction with the structure of F0F1-ATPase. Counteracting compounds (sorbitol, mannitol or inositol), despite slightly (10-20% ) inhibiting the ATPase activity, also protect the F0F1 ATPase against denaturation by urea. However, this protection was only observed at low urea concentrations (less than 1.5 м ) , and in the presence of three polyols, the Ki for urea shift from 0.7 м to 1.2 м. Urea also increases the initial activation rate of latent MgATP-SMP in a dose-dependent-manner. However, when the particles (0.5 mg/ml) were preincubated in the presence of 1 м , 2 м or 3 м urea, a decrease in the activation level occurred after 1 h, 30 and 10 min, respectively. At high MgATP-SMP concentration (3 mg/ml) a decrease in activation was observed after 2 h, 1 h and 20 min, respectively. These data indicate that the effect of urea on the activation of MgATP-SMP depends on time, urea and protein concentrations. It was also observed that polyols suppress the activation of latent MgATP-SMP in a dose-dependent manner, and protect the particles against urea denaturation during activation. We suppose that a decrease in membrane mobility promoted by interactions of polyols with phospholipids around the F0F1 ATPase may also increase the compactation of protein structure, explaining the inhibition of natural inhibitor protein of ATPase (IF1) release and the activation of the enzyme.
The Effect of the Lipid Bilayer State on Fluorescence Intensity of Fluorescein-PE in a Saturated Lipid Bilayer
Authors: Langner Marek , Pruchnik Hanna , Kubica Krystian
Published: August 2018

Fluorescein-PE is a fluorescence probe that is used as a membrane label or a sensor of surface associated processes. Fluorescein-PE fluorescence intensity depends not only on bulk pH, but also on the local electrostatic potential, which affects the local membrane interface proton concentration. The pH sensitivity and hydrophilic character of the fluorescein moiety was used to detect conformational changes at the lipid bilayer surface. When located in the dipalmitoylphosphatidylcholine (DPPC) bilayer, probe fluorescence depends on conformational changes that occur during phase transitions. Relative fluorescence intensity changes more at pretransition than at the main phase transition temperature, indicating that interface conformation affects the condition in the vicinity of the membrane. Local electrostatic potential depends on surface charge density, the local dielectric constant, salt concentration and water organisation. Initial increase in fluorescence intensity at temperatures preceding that of pretransition can be explained by the decreased value of the dielectric constant in the lipid polar headgroups region related in turn to decreased water organisation within the membrane interface. The abrupt decrease in fluorescence intensity at temperatures between 25 °C and 35 °C (DPPC pretransition) is likely to be caused by an increased value of the electrostatic potential, induced by an elevated value of the dielectric constant within the phosphate group region. Further increase in the fluorescence intensity at temperatures above that of the gel-liquid phase transition correlates with the calculated decreased surface electrostatic potential. Above the main phase transition temperature, fluorescence intensity increase at a salt concentration of 140 m M is larger than with 14 m M . This results from a sharp decline of the electrostatic potential induced by the phosphocholine dipole as a function of distance from the membrane surface.
New Prostaglandins from the Chemically Defended Soft Coral Plexaura nina
Authors: Agalias Apostolos , Mihopoulos Nikos , Tsoukatou Maria , Marinos Lefteris , Vagias Constantinos , Harvala Catherine , Roussis Vassilios
Published: August 2018

Three new prostaglandins were isolated as minor constituents of the organic extract from the Caribbean soft coral Plexaura nina. The structures of the new natural products w ere established by means of spectral data analysis, including 2D NMR experiments. The unpalatability of the lipid extract of the coral and the defensive role of the major prostaglandin metabolites were determined by laboratory and field fish-feeding assays.
Chemical Variability of the Volatile Metabolites from the Caribbean Corals of the Genus Gorgonia
Authors: Roussis Vassilios , Vagias Constantinos , Tsitsimpikou Christina , Diamantopoulou Nina
Published: August 2018

The chemical composition of the investigated gorgonians showed a high level of individual variation and the colonies, according to their major contributors, were assigned to 10 distinct chemical profiles, among which A , C, E , and G were them ost abundant ones. From the metabolites identified in the present study, either by means of GC /MS or using NMR techniques after conventional separation procedures, the novel cyclic ether 5,10-epoxymuurolane is found in significant quantities in D and I chemical profiles. Furanotriene, isofuranotriene and furanodiene could be referred as the most common metabolites of the genus, since they are found in 6 out of 10 chemical profiles. Isosericenine is, also, a significant contributor of H and I chemical profiles. A number of sesquiterpene hydrocarbons, such as curzerene, bicyclogermacrene, valencene, β-bourbonene and β -elemene, along with the oxygenated sesquiterpenes elemanolide and furoventalene, are present at varying concentrations in the majority of the chemical profiles. Metabolites of high discriminant value are: α-himachalene for the K chemical profile, α -santalene and its oxygenated derivatives for the G chemical profile and the three geometrical isomers of germacrone for the F chemical profile.

Several chemical profiles show ed narrow geographic distribution. Most of the chemical profiles are located in the north, while F inhabits mainly southern sites and the others are equally distributed. Finally, 91 % of the chemical profiles of the gorgonian colonies appeared to grow in all depths, while 9 % did not inhabit deep -water environments. Most chemical profiles are less frequent at higher water depths with the exception of chemical profiles A and C.
The Anticancer Drug Cisplatin Interacts with the Human Erythrocyte Membrane
Authors: Suwalsky Mario , Hernández Pedro , Villena Fernando , Sotomayor Carlos P.
Published: August 2018

Drugs which exert their effects by interacting with DNA cause structural and functional membrane alterations which may be essential for growth inhibition by these agents. This paper describes the interaction of cisplatin with the human erythrocyte membrane and models constituted by bilayers of dimyristoylphosphatidylethanolamine (DMPE) and diacylphosphatidylserine (DAPS), representative of phospholipid classes located in the inner monolayer of the erythrocyte membrane, and of dimyristoylphosphatidylcholine (DMPC), a class present in its outer monolayer. Cisplatin ability to perturb DMPE, DAPS and DMPC bilayer structures was determined by X-ray diffraction and fluorescence spectroscopy. Electron microscopy disclosed that human erythrocytes incubated with 35 μм cisplatin, which is its therapeutical concentration in serum, developed cup-shaped forms (stomatocytes). According to the bilayer couple hypothesis, this means that the drug is inserted into the inner monolayer of the erythrocyte membrane, a conclusion supported by the studies on model systems.
Phytochemical and Pharmacognostic Investigation of Bauhinia forficata Link (Leguminosae)
Authors: Silva Karina L. da , Biavatti Maique Weber , Leite Silvana Nair , Yunes Rosendo A. , Monache Franco Delle , Filho Valdir Cechinel
Published: August 2018

We have isolated two phytoconstituents present in the B. forficata leaves, a medicinal plant employed in folk medicine specially for the treatment of diabetes. These compounds were isolated by column chromatography and identified as β-sitosterol and kaempferol-3,7-dirhamnoside (kaempferitrin) by spectroscopical data and comparison with authentic samples. A comparative study with different parts of the plant indicated that the latter is present only in the leaves, suggesting that it might be useful for a suitable quality control of phytotherapeutics which contain this organ of B. forficata in its composition.
Paraquat Resistance of Weeds - the Case of Conyza canadensis (L.) Cronq
Authors: Szigeti Zoltán , Rácz Ilona , Lásztity Demeter
Published: August 2018

The paper gives an overview of literature on paraquat resistance of weeds and the proposed mechanism of resistance. New results we achieved on horseweed ( Conyza canadensis /L./, Cronq.) are discussed in detail.

It was demonstrated that there is no significant constitutive difference related to the paraquat resistance between untreated susceptible and paraquat-resistant horseweed plants. The lower sensitivity of flowering resistant plants may be due to the fact that paraquat content in treated leaves of flowering resistant plants was only 25% as compared to those measured at rosette stage. Our results confirm that paraquat resistance is not based on elevated level and activity of antioxidant enzyme system. The hypothesized role of polyamines in the resistance mechanisms can be excluded. The higher putrescine and total polyamine content of paraquat treated resistant leaves can rather be regarded as a general stress response, than as a symptom of paraquat resistance. A paraquat-inducible protein is supposed to play a role in the resistance, which presumably functions by binding paraquat to an inactivating site and/ or by carrying paraquat to metabolically inactive cell compartment (vacuole, cell wall). From model experiments it is concluded that paraquat and diquat preferentially form hydrophylic interactions with proteins containing a higher amount of lysine and glutamic acid. Consequently, the reason for paraquat resistance in horseweed is probably a hydrophylic interaction of paraquat with a protein, leading to inactivation of paraquat through forming a conjugate and/or sequestration into the vacuole or the cell wall.
Acetylcholinesterase and Insect Growth Inhibitory Activities of Gutierrezia microcephala on Fall Army worm Spodoptera frugiperda J. E. Smith
Authors: Calderón José S. , Céspedes Carlos L. , Rosas Rosaura , Gómez-Garibay Federico , Salazar Juan R. , Salazar Juan R. , Lina Laura , Aranda Eduardo , Kubo Isao
Published: August 2018

From the aerial parts of Gutierrezia microcephala (Asteraceae), four oxyflavones were isolated, namely 5,7,2′-trihydroxy-3,6,8,4′,5′-pentamethoxyflavone (1); 5,7,4′-trihydroxy-3,6,8-trimethoxyflavone (2); 5,7,2′,4′-tetrahydroxy-3,6,8,5′-tetramethoxyflavone (3); 5,2′-dihydroxy- 3,6,7,8,4′,5′-hexamethoxyflavone (4), and an ent-clerodane, bacchabolivic acid (5). Compounds 1-5, the synthetic methyl ester (6 ), n-hexane and MeOH extracts were evaluated against the fall armyworm (Spodoptera frugiperda). Gedunin, a known insect growth regulator isolated from Cedrela spp. was used as a positive control. When tested for activity on neonate larvae into the no-choice artificial diet bioassay, flavone (1), clerodane (5), its methyl ester (6), MeOH and n-hexane extracts caused significant larval mortality with MC50 of 3.9, 10.7, 3.46. 7.95 and 7.5 ppm at 7 days, respectively, as well as growth reduction. They also increased the development time of surviving larvae and a significant delay in time to pupation and adult emergence. Acute toxicity against adults of S. frugiperda was also found, 5, 6 , gedunin and n-hexane extract had the most potent activity with LD50 value of 6.59, 15.05, 10.78, and 12.79 ppm, respectively. In addition, MeOH, n-hexane extracts, 5, 6 and gedunin caused acetylcholinesterase inhibition with 93.7,100,90.2,62.0 and 100% at 50.0 ppm, respectively; whereas 1-4 exhibited only moderate inhibitory activity. Compounds 1,5 and 6 showed inhibitory activities comparable with gedunin. These compounds could be responsible of the insect growth inhibitory activity of this plant.
Site-Directed Mutagenesis of Proline-285 to Leucine in Cephalosporium acremonium Isopenicillin N - Synthase Affects Catalysis and Increases Soluble Expression at Higher Temperatures
Authors: Loke Paxton , Sim Tiow-Suan
Published: August 2018

The conversion of δ-(ʟ-α-aminoadipyl)-ʟ-cysteinyl-ᴅ-valine (ACV) to isopenicillin N is dependant on the catalytic action of isopenicillin N - synthase (IPNS), an important enzyme in the penicillin and cephalosporin biosynthetic pathway. One of the amino acid residues suggested by the Aspergillus nidulans IPNS crystal structure for interaction with the valine isopropyl group of ACV is proline-283. Site-directed mutagenesis of the corresponding proline- 285 to leucine in Cephalosporium acremonium IPNS resulted in non-measurable activity but an increased soluble expression at higher temperatures in a heterologous E. coli host.
Constant Expression of Cyclooxygenase-2 Gene in Prostate and the Lower Urinary Tract of Estrogen-Treated Male Rats
Authors: Luo Cheng , Strauss Leena , Ristimäki Ari , Streng Tomi , Santti Risto
Published: August 2018

Expression of cyclooxygenase-2 (E. C. 1.14.99.1) in prostate and the lower urinary tract (LUT) of the neonatally estrogenized male rat has been studied by using a COX-2 ’s PCR fragment of 724 nt spanning 3 introns and a 478nt internal standard for quantitative RTPCR. The same fragment of 724 nt was used for RNA probe in Northern hybridization. Neonatal estrogenization (10 μg/day of diethylstilbestrol on days 1-5) had no effect on COX -2 expression in prostatic urethra, prostatic lobes, or bladder. Acute estrogen treatment of castrated animals did not induce COX-2 expression, either. In addition the differential expression of basal level of COX-2 in the different lobes of prostate in normal rat was demonstrated. Our results suggest a constant expression of COX-2 gene in prostate and the lower urinary tract of the neonatally estrogenized (neoDES) rats. The present study indicates that the increased expression of COX -2 is probably not essential for the estrogen-driven development of stromal inflammation or hyperplastic and dysplastic alterations in the prostate of neoDES rats.
Nuclei of Plants as a Sink for Flavanols
Authors: Feucht Walter , Polster Jürgen
Published: August 2018

Onion cepa (L.) and Tsuga canadensis (L.) Carr, were investigated histochemically on the association of flavanols to nuclei. The young roots of Onion cepa are totally devoid of flavanol structures. Therefore, the excised roots tips were directly incubated into different solutions of flavanols. After 3 h of incubation a flavanol binding on the nuclei was recognizable, as seen by a yellowishbrown tanning reaction. Still to ensure the presence of flavanols on the nuclei, subsequent staining with the pdimethylaminocinnamaldehyde reagent (DMACA) resulted in an intense blue colouration. Tsuga canadensis has significant amounts of vacuolar flavanol deposits in all parts of the tree as indicated by the DMACA reagent. It is obvious that also the nuclei were associated strongly with flavanols which can be demonstrated particularly elegant in the cells of the seed wings by histochemical methods. However, the mode of flavanol release from the original deposits is not yet clear.
Tropical Town and Other Poems (1918) de Salomón de la Selva: poemas panamericanos en tiempos de la Gran Guerra
Authors: Suarez Turriza Tatiana de los Reyes
Published: August 2018

Tropical Town and Other Poems (1918) es el único poemario de Salomón de la Selva publicado en inglés, en el contexto de la Gran Guerra. Se le considera una obra de coyuntura entre dos culturas y tradiciones literarias.  Este trabajo plantea la importancia de considerar su estudio en el ámbito de las letras hispánicas, entre otras razones, por su evidente relación con la tradición poética hispanoamericana. A partir del análisis crítico de los poemas, se evidencia la expresión de un discurso ideológico fundamentado en los ideales del panamericanismo, postura de implicaciones políticas que fue definitiva en la vida y obra del autor. Se analiza dicho discurso como una de las directrices temáticas que estructura y da unidad a la obra. Asimismo, se expone la calidad estética del poemario, a partir del análisis de algunos recursos poéticos.
Política pública de preservação ferroviária em Bauru (SP): os desdobramentos da criação de programas nacionais e conselhos representativos na década de 1980
Authors: Losnak Sérgio Ricardo , Oliveira Eduardo Romero de
Published: August 2018

Este trabalho busca caracterizar as políticas públicas de preservação no estado de São Paulo, mais especificamente da cidade de Bauru, tendo como objetos o Conselho de Defesa do Patrimônio Cultural e o Museu Ferroviário Regional. Esses mecanismos de proteção estão presentes em muitos municípios e se tornaram a principal ferramenta de preservação de bens ferroviários. Em termos metodológicos, o trabalho contou com pesquisa bibliográfica exploratória sobre o tema, análise documental e entrevistas com agentes envolvidos no processo. Como resultado, chegou-se à compreensão das diretrizes, conceitos, valores e agentes que atuam na preservação por meio das políticas públicas, indicando-nos o método de musealização como prática principal quando se trata do patrimônio industrial ferroviário, não só na cidade de Bauru como em outros municípios do estado de São Paulo.
Neurodevelopment After Perinatal Arterial Ischemic Stroke
Authors: Wagenaar Nienke , Martinez-Biarge Miriam , van der Aa Niek E. , van Haastert Ingrid C. , Groenendaal Floris , Benders Manon J.N.L. , Cowan Frances M. , de Vries Linda S.
Published: August 2018

BACKGROUND AND OBJECTIVES:

Perinatal arterial ischemic stroke (PAIS) leads to cerebral palsy in ∼30% of affected children and has other neurologic sequelae. Authors of most outcome studies focus on middle cerebral artery (MCA) stroke without differentiating between site and extent of affected tissue. Our aim with this study was to report outcomes after different PAIS subtypes.

METHODS:

Between 1990 and 2015, 188 term infants from 2 centers (London [n = 79] and Utrecht [n = 109]) had PAIS on their neonatal MRI. Scans were reevaluated to classify stroke territory and determine specific tissue involvement. At 18 to 93 (median 41.7) months, adverse neurodevelopmental outcomes were recorded as 1 or more of cerebral palsy, cognitive deficit, language delay, epilepsy, behavioral problems, or visual field defect.

RESULTS:

The MCA territory was most often involved (90%), with posterior or anterior cerebral artery territory strokes occurring in 9% and 1%, respectively. Three infants died, and 24 had scans unavailable for reevaluation or were lost to follow-up. Of 161 infants seen, 54% had an adverse outcome. Outcomes were the same between centers. Main branch MCA stroke resulted in 100% adverse outcome, whereas other stroke subtypes had adverse outcomes in only 29% to 57%. The most important outcome predictors were involvement of the corticospinal tracts and basal ganglia.

CONCLUSIONS:

Although neurodevelopmental outcome was adverse in at least 1 domain with main branch MCA stroke, in other PAIS subtypes outcome was favorable in 43% to 71% of children. Site and tissue involvement is most important in determining the outcome in PAIS.
Rural Area Learners’ Writing Self-efficacy Development: A Qualitative and Quantitative Approaches
Authors: Jalaluddin Ilyana
Published: August 2018

This case study aimed to evaluate the rural area learners’ writing self-efficacy using two different approaches which are qualitative and quantitative approach. It involved three form four students and a teacher for six months. In this study, the learners’ writing self-efficacy was investigated using a combination of quantitative and qualitative (classroom observation). Classroom observation was based on three characteristics: persistence in accomplishing language tasks, self-awareness of English proficiency, and willingness to engage in language activities. These characteristics which were concept of self-efficacy. This study did not focus on the score of WSE scales alone but also placed a heavy emphasis on the perceptions and actions of the form four students and teacher. Altogether, 15 non-participant classroom observations, 10 interviews with each of the three students and 10 teacher’s interviews were carried out to understand the participants’ self-efficacy phenomena in their learning to write. Findings showed that the combination of different method of collecting data for writing self-efficacy was a feasible way in explaining rural learners’ writing self-efficacy development.