bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Survey of Phytoalexin Induction in Leaves of the Rosaceae by Copper Ions
Authors: Kokubun Tetsuo , Harborne Jeffrey B. 
Published: August 2018

Abstract
The leaves of 130 species of Rosaceae were surveyed for phytoalexin induction. Both biotic and abiotic induction was examined and antifungal compounds were detected in 47 species. However, these compounds appeared to be constitutive metabolites, released from bound phenolic materials already present in the leaf. In Pyrus, hydroquinone was produced from the hydrolysis of arbutin present in the vacuole before inoculation. In most other species, the fungitoxic agents were mainly catechin-like derivatives, apparently released from the tannins present within the leaf. By contrast, the synthesis in the leaf of the characteristic biphenyl or benzofuran phytoalexins which are produced in sapwood, was confined to a very few species. The biphenyl aucuparin was identified as a phytoalexin from the leaves of Sorbus aucuparia.
Modulation of Cell-Mediated Immunity by Lithium Chloride
Authors: Kubera M. , Bubak-Satora M. , Holan V. , Krol W. , Basta-Kaim A. , Roman A. , Skowron-Cendrzak A. , Shanid J. 
Published: August 2018

Abstract
Immunomodulation of cell-mediated immunity was studied in mice treated with either lithium chloride (LiCl), anti-CD 8 monoclonal antibody or their combination. While 6-day LiCl treatment decreased the ability of their splenocytes to induce a local graft-versus-host reaction -anti-CD 8 abolished this effect. The proliferative response of spleen cells from those three groups of mice to concanavalin A stimulation in vitro was significantly increased. The natural killer (NK) cell toxicity of the mice was decreased by over 43% after the 6-day LiCl treatment, but was ×2.5 higher then the control value after a longer 21-d treatment. These results indicate that the immunomodulatory capacity of lithium is dependent on the type of cell population studied, and on the schedule of administration.
Stereospecific Reduction of /R(+)-Thioctic Acid by Porcine Heart Lipoamide Dehydrogenase/Diaphorase
Authors: Schempp H. , Ulrich H. , Elstner E. F. 
Published: August 2018

Abstract
R(+)-thioctic acid is the naturally occurring cofactor in α-ketoacid dehydrogenases. We show both photo­ metrically by NADH + H+ oxidation and by HPLC prod­uct analysis that this enantiomer is rapidly reduced by NADH + H+ catalyzed by porcine heart lipoamide dehydrogenase/diaphorase. The racemate exhibits approxi­ mately 40% activity as compared to the R (+) form while the S (-) enantiomer photometrically shows little activity and yields no detectable reduced lipoic acid.
Arom atic Amino Acid and Amine Levels in the Hemolymph of Parasitized and Unparasitized Larvae of Mythimna separata
Authors: Shimizu T. , Takeda N. 
Published: August 2018

Abstract
The levels of aromatic amino acids and amines in the hemolymph of larvae of the common armyworm, My­ thimna separata, were analyzed after parasitization by the braconid wasp, Apanteles kariyai. Methyldopa, homovanillic acid, tryptophan and tyrosine remained unchanged in unparasitized and parasitized larvae. Dopamine and DOPA showed characteristic changes at pupation that were associated with the hardening and darkening of the cuticle; Dopamine in the hemolymph of unparasitized last instar larvae increased before pu­pation. Large increases in kynurenine and octopamine were detected in parasitized larvae. The increased level of octopamine in the hemolymph may be stress related.
Ribonucleosides in Human Milk. Concentration Profiles of These Minor Constituents as a Function of the Nursing Time
Authors: Schlimme Eckhard , Schneehagen Kirsten 
Published: August 2018

Abstract
Ribonucleosides are secreted as products of cellular RNA and ribonucleotide metabolism into physiological fluids such as blood, milk and urine. Unmodified and modified ribonucleo­sides have been detected in the micromolar range as minor constituents in the milk of differ­ent mammals. In addition to the common nucleosides adenosine, cytidine, guanosine, inosine and uridine, modified components such as 1-methyladenosine, 1-methylguanosine, 1-methylinosine, N2-methylguanosine, N2-dimethylguanosine, N6-carbamoyl-ʟ-threonyladenosine, pseudouridine and 5-aminoimidazole-4-carboxamide-N-ribofuranoside (AICAR) have been identified and most of them quantified in samples of human and/or bovine and/or goat’s milk. From these investigations it is known that nucleosides, in analogy to nucleotides, show a typical species-specific pattern. Longitudinal studies have been carried out to determine the concentration profiles of the individual ribonucleosides in the milk of humans as a function of the nursing time.
Interaction of Organophosphorus Insecticide Methylparathion with Calf Thymus DNA and a Synthetic DNA Duplex
Authors: Blasiak Janusz , Kleinwächter Vladimír , Walter Zofia , Žaludová Renata 
Published: August 2018

Abstract
The interaction of an organophosphorus insecticide methylparathion (O.O-dimethyl 0-4-nitrophenyl phosphorothioate) with double-stranded DNA was characterized by UV and circular dichroism (CD) spectroscopy. Two kinds of DNA were employed: calf thymus DNA (CT DNA) and a synthetic two-stranded oligomer of sequence 5′-d(TTGGATCCGAATT-CAAGCTT)-3′ Melting curves and CD spectra were taken for the DNAs in the presence of the insecticide at methylparathion/DNA base pair molar ratio of 0.5. The insecticide evoked a decrease of the melting temperature and a broadening of the transition range for CT DNA. Similar effects were observed for the synthetic oligomer but they were less pronounced than in the case of CT DNA. Methylparathion evoked a slight shift and an increase in the amplitude of the negative band in the CD spectra of both DNAs. Obtained results indicate that methylparathion may perturb the thermal stability and conformation of DNA, which is an evidence that the insecticide has an ability to interact directly with DNA.
Involvement of Oxidative Burst in Isoflavonoid Metabolism in Elicited Cell Suspension Cultures of Pueraria lobata
Authors: Park Hyung-Hwan , Hakamatsuka Takashi , Sankawa Ushio , Ebizuka Yutaka 
Published: August 2018

Abstract
Hydrogenperoxide exogenously administerd to the suspension-cultured cells of Pueraria lobata stimulated a rapid disappearance of the constitutive isoflavonoids (malonylglucosides of daidzein and genistein) from the methanol soluble fraction of the cells, in a similar manner as observed in the cells treated with yeast extract or glycoprotein preparation of Phyto­phthora megasperma f. sp. glycinea. Rapid generation of H2O2 was detected within 10 min after elicitation at the cell surface, presumably preceded by the activation of plasma membrane NAD(P)H-oxidases. Pretreatment of some representative NAD(P)H-oxidase inhibitors such as SHAM, DEDTC and KCN (1 mᴍ each) to the cells 1 h before elicitation resulted in almost complete inhibition of the elicitor-stimulated metabolism of isoflavonoids for 4 h, whereas treatment of the inhibitors at 1 h after elicitation showed no significant effect on the rapid isoflavonoid metabolism. These findings suggest that this type of response to elicitation could be regarded as a plausible initial defense strategy prior to the appearance of de novo synthesized defensive barriers such as phytoalexins and lignin in plant-pathogen interaction.
The Effect of Weak Permanent Magnetic Fields on the Electric Properties of Lipid-Bilayers
Authors: Pazur Alexander 
Published: August 2018

Abstract
Black lipid membranes were prepared on a Teflon septum separating electrically the two chambers of a Teflon cuvette, using the technique of Mueller et al., (Nature 194. 979 (1962)). An external, static magnetic field was applied, whose intensity varied from 0 G to 100 G at the membrane location. Field applications higher than 10 G are effecting higher leakage currents, increased capacity and faster breakdown of the bilayer state, as compared to the absence of a magnetic field. If bilayers were doped with chlorophyll a, these effects were increased. Quantum mechanical and thermodynamical phenomena on membranes will be discussed as possible origins of these effects.
Protective Effect of Amphiphilic Ammonium Salts on the Oxidation of Lecithin Liposomes
Authors: Gabrielska J , Kleszczyriska H , Przestalski S 
Published: August 2018

Abstract
The inhibition effect of selected amphiphilic quaternary alkyl-substituted ammonium salts on oxidation of the lecithin liposome membrane was studied, induced by ultraviolet light and Fe2+ ions with ascorbic acid added. The salts differed in alkyl chain length Ri having the following alkyl substitutents: R1 = C9H19; R2 = C10H21; R3 = C12H25; R4 = CH2OC14H29; R5 = CH2OC16H33.
It was found that all the salts used induced inhibition in oxidation of the liposome membrane, both that induced by UV light and ferrous ions. The antioxidant activity of the salts studied, dependent on the chain length and concentration, can be represented by the relation R1 < R2< R3 < R4 < R5. A similar dependence was obtained when the hemolytic activity
of compounds was studied. Activity of salts increase with alkyl chain length.
Involvement of Thiol Groups in Blue-Light-Induced Phosphorylation of a Plasma Membrane-Associated Protein from Coleoptile Tips of Tea mays L.
Authors: Rüdiger Wolfhart , Briggs Winslow R. 
Published: August 2018

Abstract
Light-induced phosphorylation of a 114 kDa protein in plasma membranes isolated from the tips of maize coleoptiles was investigated in the presence of several thiol reagents at the concentration of 1 mᴍ. Dark phosphorylation of the protein was not affected but lightinduced phosphorylation was inhibited 50% with iodoacetamide, 75% with N-ethylmaleimide and 93% with N-phenylmaleimide. Previous incubation of the inhibitors with mercaptoethanol abolished the inhibitory activity completely. N-phenyl-maleimide showed the same inhibition whether it was applied before or after irradiation of the sample. Involvement of thiol group(s) in processes after photoexcitation is discussed.
Further Characterization of Aspartate Aminotransferase from Haloferax mediterranei: Pyridoxal Phosphate as Coenzyme and Inhibitor
Authors: García-Muriana Francisco J. , Alvarez-Ossorioa María C. , Sánchez-Garcés María M. , Rosa F. de la , Relimpio Angel M. 
Published: August 2018

Abstract
The enzyme aspartate aminotransferase has been isolated from the halophilic bacterium Haloferax mediterranei in its apoenzyme form. The interaction with its coenzyme (pyridoxal phosphate) has been investigated. For concentrations up to 0.05 mᴍ, the incubation with pyridoxal phosphate reconstituted the active complex (holoenzyme) following a second order kinetic with a k2 of 5.2 min-1mᴍ-1. This active complex showed a dissociation constant (Kd) of 7.8 x 10-6 ᴍ. For concentrations higher than 0.1 mᴍ, pyridoxal phosphate produced an inactivation process with a complex second order kinetic. This inactivation is partially reverted by dialysis or by lysine treatment. Thus, after 80% of inactivation, 55% of the original activity is recovered by a long-time dialysis, and with 50 mᴍ lysine also a partial reactivation (among 20-33%) is observed. The enzyme treated with 1 mᴍ pyridoxal phosphate has a different behavior in Sepharose chromatography indicating that the modified enzyme presents a smaller size due to a conformational change.
Plant Disease Resistance Inducing Activity of 7-Oxo- and 7-Hydroxysterols
Authors: Schabdach H. , Johne S. , Steiner U. , Seifert K. 
Published: August 2018

Abstract
The 7-oxosterols 1-2 and the 7-hydroxysterols 3-6 induce resistance toward the fungal pathogens Puccinia striiformis West, and Puccinia hordei Otth in barley and wheat. Primary leaves of the plants were sprayed with solutions of the compounds ( 10-4 mol/l in 1% aqu. ethanol) followed, 2 days later, by challenge inoculation with the fungal pathogens. The results indicate that 7α- and 7β-hydroxylated epimers of β-sitosterol and cholesterol show the highest value of induced resistance (39-49% reduction of infection sites). No enhanced resistance toward the fungi Erysiphe graminis DC f.sp. tricitic and hordei and Cochliobolus sativus Ito & Kuribayashi was observed.
The Mesenchyme-Like Layer of the Fiber Cells of Trichoplax adhaerens (Placozoa), a Syncytium
Authors: Buchholz Katja , Ruthmann August 
Published: August 2018

Abstract
The fiber cells of the middle layer of Trichoplax adhaerens are interconnected by slender extensions. Newly formed connections after mechanical disruption of the tissue studied in ultrathin sections revealed cytoplasmic continuity between the cell bodies, suggesting a syncytial organisation of the fiber cell layer. The slender extensions connecting the cell bodies are traversed by microtubules and microfilaments. The structure of rare osmiophilic cell contacts suggests a stage in the fusion of adjacent cell membranes.
Age Dependence of Murine Spermatogenesis
Authors: Hacker-Klom Ursula Beate 
Published: August 2018

Abstract
The dependence of spermatogenesis function on murine age shall be investigated. Thus, testicular samples of at least 10 NMRI mice per group aged 0 to 26 months are analysed by flow cytometry after staining the DNA with DAPI. The aim of this study is to be able to account for the influence of age on mice.
There are no changes in spermatogenesis in mice aged 11 weeks up to 16 months with respect to testis weight and to the frequency of different testicular cell types. From 16 months onwards, there is a tendency to a reduced spermatogenesis function; The frequency of round spermatids is decreased. In addition, there is an increased chromatin dispersion in elongated spermatids with age. Thus, older mice (>16 months) should not be used for experiments e.g. on radiation and drug effects any more. The frequency of abnormal diploid spermatozoa does not increase with age.
Limits of Natural Science: Brain Research and Computers
Authors: Stieve Hennig 
Published: August 2018

Abstract
The criterion that pure natural science can only investigate objective phenomena which can be observed by independent observers sets certain limits to our scientific understanding of brain functions. The methods and the present state of brain research and of computer development are described. The limitations of brain research are discussed by comparing the properties of brains and computers. At least for the time being we do not know of any natural scientific -i.e. physical or chemical -method which allows the objective measurement of consciousness, sensations, and emotions.
Pyoverdin, Ferribactin, Azotobactin -a New Triade of Siderophores from Pseudomonas chlororaphis ATCC 9446 and Its Relation to Pseudomonas fluorescens ATCC 13525
Authors: Hohlneicher U. , Hartmann R. , Taraz K. , Budzikiewicz H. 
Published: August 2018

Abstract
It is shown that Pseudomonas fluorescens ATCC 13525 and Pseudomonas chlororaphis ATCC 9446 produce identical pyoverdins and ferribactins. As the structures of these sidero­ phores are usually species or even strain specific this exception should be kept in mind in view of the reclassification of the genus Pseudomonas. From Pseudomonas chlororaphis an additional siderophore could be obtained which has the same peptide chain as the co-occur­ ring pyoverdins and ferribactin, but a chromophore which is typical for azotobactins from Azotobacter vinelandii.
Properties of a Dissimilatory Nitrate Reductase from the Halophilic Archaeon Haloferax volcanii
Authors: Bickel-Sandkötter Susanne , Ufer Martina 
Published: August 2018

Abstract
Grown under anaerobic conditions in presence of nitrate, Haloferax volcanii shows nitrate reduction and accumulation of nitrite in the culture medium. We found a membrane-associated nitrate reductase, which could easily be solubilized by gently stirring of isolated membranes. Surprisingly, this nitrate reductase requires no NaCl for its activity. A medium pH of 7.5 and high temperatures up to 80 °C are necessary for optimum activity. Kinetic studies showed that the apparent Kᴍ was 0.36 mmol/l for nitrate and 80 μmol/l for dithionite-reduced methyl viologen. The respiratory chain inhibitor cyanide effects nitrate reduction noncompe-titively with respect to nitrate with a Ki of 0.3 mmol/l. Azide was a strong inhibitor: The concentration required for half maximal inhibition was 60 μmol/l, whereas thiocyanate and chlorate were much weaker inhibitors. The isolated enzyme was partially purified by frac­tionated precipitation using polyethylene glycol. SDS gel electrophoresis resulted in three putative subunits of the nitrate reductase of molecular masses of about 100, 61, and 31 kDa.
The Role of Phosphatidylglycerol as a Functional Effector and Membrane Anchor of the D1-Core Peptide from Photosystem II-Particles of the Cyanobacterium Oscillatoria chalybea
Authors: Kruse O. , Schmid G. H. 
Published: August 2018

Abstract
The intrinsic polypeptide D1, isolated from photosystem (PS) Il-particles of the cyanobacterium Oscillatoria chalybea, was obtained by electroelution and fractionated extraction with organic solvents. Purification was demonstrated by Western blotting and amino acid sequenc­ing. By carrying out D1 -immunization in rabbits a polyclonal monospecific D1-antiserum was obtained.
For the qualitative characterization of D1 as a lipid-binding peptide, the effect of the lipids phosphatidylglycerol (PG), monogalactosyldiacylglyceride (MGDG) and phosphatidylcho­ line (PC) on PSII-oxygen evolution was analysed in reconstitution experiments. In these experiments purified photosystem II (PSII)-particle preparations were treated with the en­zyme phospholipase A2 and supplemented with lipid emulsions. We were able to show that the inhibition of electron transport, as the consequence of this lipase treatment, was only relieved, if phosphatidylglycerol was added to the preparation. A model was proposed, in which phosphatidylglycerol is a functional effector for the optimal conformation of D1 in the PSII core complex. Phosphatidylglycerol molecules are unusually tightly bound to the D1 peptide by hydrophobic interactions. A covalent binding seems not probable. The localisation of phosphatidylglycerol binding sites was found by trypsin treatment of D1 and analysis of the obtained oligopeptides with HPLC and immunoblotting. The binding sites could be confined to the hydrophobic amino acid section between arginine 27 and arginine 225, which is known to be the membrane anchor of D1. This has led us to the conclusion that the phospho­lipid phosphatidylglycerol plays an important role for anchoring the D1-peptide and for its orientation in the thylakoid membrane. Phosphatidylglycerol with its high amount of palmitic acid has in prokaryotic cyanobacteria apparently a role in stabilization and orientation.
The high turn-over of D1 and the spatial separation of the synthesis-and incorporation-site in the membrane, developed during evolution in eukaryotic organisms, might have changed the requirement on the mobility and the orientation of D1 in photosynthetic membranes.
Antifungal Compounds Induced in the Dual Culture with Phytolacca americana Callus and Botrytis fabae
Authors: Kobayashi Akio , Hagihara Kohtatsu , Kajiyama Shin-ichiro , Kanzaki Hiroshi , Kawazu Kazuyoshi 
Published: August 2018

Abstract
In order to investigate new metabolites which are only induced in a plant callus infected by a pathogenic fungus, dual cultures with combinations of 10 species of fungi and 6 plant cell lines from different species were established. Among the combinations tested, the methanolic extract of a dual culture consisting of a plant cell line, Phytolacca americana and a fungus, Botrytis fabae showed a marked antifungal activity to Cladosporium herbarum. The main active constituent of this extract was identified to be phytolaccoside B (Pls B) by the spectroscopic analyses.
5-Hydroxy-3-vinyl-2(5H)-furanone -a New Inhibitor of Human Synovial Phospholipase A2 and Platelet Aggregation from Fermentations of a Calyptella Species (Basidiomycetes)
Authors: Lorenzen Kirsten , Anke Timm , Konetschny-Rapp Silvia , Scheuer Werner 
Published: August 2018

Abstract
5-Hydroxy-3-vinyl-2(5H)-furanone, a potent and selective inhibitor of human synovial phospholipase A2 was isolated from fermentations of a Calyptella species. Its structure as identified by spectroscopic methods is identical to PA 147, an antibiotic previously isolated from a streptomycete. 5-hydroxy-3-vinyl-2(5H)-furanone inhibits the aggregation of human and bovine platelets stimulated by different inducers and exhibits weak antimicrobial activities.
Secretion of Neutral and Acid DNases in Cultivated Human Lymphocytes after Incubation with DNA; Possible Consequences for Inhalation Anesthesia
Authors: Reitz Manfred , Löber Günter , Kleemann Peter , Dick Wolfgang 
Published: August 2018

Abstract
After incubation with DNA human lymphocytes release neutral and acid DNase activities into the culture medium; the release depends on DNA concentration and time of cultivation. The electrophoretic mobility of the released neutral DNase activity is in accordance with DNase I and the electrophoretic mobility of the released acid DNase activity with DNase II. The released DNase activities do not originate from dead cells and are not influenced by blast cell formation. The anesthetic halothane can inhibit the released neutral and acid DNase activities. Inhalation anesthesia can possibly disturb the correlation between DNA and DNases in human blood.
Periodic Current Injection (PCI) -A New Method to Image Steady-State Membrane Potential of Single Neurons in situ Using Extracellular Voltage-Sensitive Dyes
Authors: Borst Alexander 
Published: August 2018

Abstract
A new method is described which allows to image the steady-state distribution of m em ­ brane potential of single neurons in situ. The method consists of staining the tissue with an extracellular voltage-sensitive dye (Di-4-ANEPPS) and impaling a single neuron with a microelectrode. After focusing the imaging system onto the cell a large series of images are taken with a CCD camera at the appropriate excitation wavelength of the voltage-sensitive dye while the neuron’s membrane potential is shifted by a periodic current injection (PCI). Afterwards two groups of images are averaged separately: those images while the cell was at rest and those images while the cell was hyperpolarized. After subtraction of these averaged images, the resulting difference image shows only the membrane potential of the cell which was altered periodically. The success of the method is demonstrated on leech cells in intact ganglia. If applied to cells with a basically two-dimensional arborization pattern, the decrease of activity in the difference image in areas further away from the injection site should relate to a decrease in membrane potential according to the passive electrotonic properties of the cell under study.
Studies on Sporopollenin Structure during Pollen Development
Authors: Meuter-Gerhards Andrea , Schwerdtfeger Claus , Steuernagel Stefan , Wilmesmeier Sabine , Wiermann Rolf 
Published: August 2018

To clarify whether the structure of sporopollenin varies during pollen development FTIR and 13C NMR spectroscopic analyses of Tulipa and Cucurbita sporopollenin from three different developmental stages were carried out.
The spectra of sporopollenin obtained from an early, a middle postmeiotic and the mature stage have been compared. The assumption that sporopollenin mainly consists of long chain aliphatics with varying amounts of aromatics is corroberated by our results.
Only slight changes in sporopollenin structure could be recognized during pollen wall development of Cucurbita maxima. In contrast to this the spectra of Tulipa sporopollenin of the three developmental stages exhibited significant differences concerning the aliphatic and aromatic components.