bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth and Myelination of Goldfish Optic Nerve Fibers after Retina Regeneration and Nerve Crush
Authors: Wolburg Hartwig 
Published: August 2018

Abstract
Axonal regeneration in the optic nerve and tectum of the goldfish was studied both after retina regeneration and nerve crush. The retina regeneration was evoked by ouabain-induced damage of at least the ganglion cells and cells of the inner nuclear layer. The necrotic retinal neurons are substituted by mitotic processes in the outer nuclear layer and the marginal growth zone at the ora serrata. The axons of these newly developed retina ganglion cells grow through the degenera­ ting. but mechanically undamaged, optic nerve into the tectum, establishing there synaptic contacts already 16 days after the intraocular ouabain-injection. The fibers were myelinated at first in the tectum, later on in the optic nerve. Thus, the myelination process proceeds in retrograde direction. About 60 - 80 days after injection the myelination has become nearly normalized. On the contra­ lateral side of the same animal, the optic nerve was crushed near the eye-bulb. The axons of the original retina ganglion cells grow out into the degenerating optic nerve and tectum. They also find synaptic contacts and are myelinated in retrograde direction, but to a much lesser extent than the axons of the regenerated retina ganglion cells. An axonal factor is discussed, which would influence the oligodendroglial myelination activity. The effectiveness of this factor is probably dependent on the neuronal age and suggested to be triggered by the establishment of synaptic contacts.
A Sex Attractant for the Pine Beauty Moth, Panolisflammed
Authors: Priesner Ernst , Bogenschütz Hermann , Altenkirch Wolfgang , Arn Heinrich 
Published: August 2018

Abstract
Electrophysiological recordings from antennal hair sensilla of male P. flammea revealed two types (A, B) of presumed pheromone receptor cells. The A receptors responded max­ imally to (Z)-9-tetradecenyl acetate and the B cells to (Z)-11-tetradecenyl acetate. In the field, a 100:5 mixture of the two compounds attracted 10 times more males than the (Z) -9 isomer alone.
On the Evolution of an Oligocephalic Enzyme. Glutamine- Chorismate-Amidotransferase-Free Anthranilate Phosphoribosyltransferases from Mutant Strains of Salmonella typhimurium
Authors: Grieshaber Manfred 
Published: August 2018

(1) A procedure has been described for the purification of two glutamine-chorismate-amido- transferase-free anthranilate phosphoribosyltransferases from mutant strains TAX6trpR782 and trpAB1653trpR782 of Salmonella typhimurium.
(2) The native enzymes tend to aggregate forming polymers of molecular weights 333,000 in the case of TAXtrpR782 and 220,000 and larger than 1X106 in the case of trpABI653trpR782. In the presence of sodium dodecyl sulfate the polymer of trpAB1653trpR782 dissociates into a single component with molecular weight of 72,000.
(3) In contrast to anthranilate phosphoribosyltransferase of the wild type component II, the glutamine-chorismate-amidotransferase-free proteins do not complex with component I. They do however show catalytical similarities with the wild type with respect to anthranilate phosphoribosyltransferase activity.
Inhibition of Millisecond Luminescence by Copper(II) in Spinach Chloroplasts
Authors: Vierke Gerhard , Struckmeier Peter 
Published: August 2018

Abstract
Intoxication of class II chloroplasts of spinach with Cu(II) leads to inhibition of millisecond luminescence. The degree of inhibition depends on Cu (II) -concentration. The investgation of the pH dpendence of the inhibition curve of luminescence revealed that (1) there is an inhibition site of copper on the donor side of photosystem II, (2) copper (II) does not act as an uncoupler of photophosphorylation, (3) a protonation equilibrium is involved in the inhibition mechanism, and (4) copper (II) binds to a dissociated residue of a membrane protein.
Interactions of Protons with Transitions of the Watersplitting Enzyme of Photosystem II as Measured by Delayed Fluorescence
Authors: Bowes Jane M. , Crofts Antony R. 
Published: August 2018

Abstract
By measuring ms delayed fluorescence emission, we have investigated the interaction of protons in the reactions of the watersplitting enzyme of photosystem II.
(1) In the presence of the electron transport mediators 2,3,5,6-tetramethyl-p-phenylene diamine (DAD) (in its reduced form) and methyl viologen and of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), the maximal intensity of the delayed fluorescence measured between 1 and 1.5m s after illumination was greater than the level reached in the presence of DCMU alone.
(2) The stimulation of the delayed fluorescence was greater when the suspension was preilluminated by 1 - 8 xenon (or laser) flashes prior to addition of DCMU, and the maximal intensity varied with the number of preilluminating flashes given.
(3) The amplitude of the intensity of delayed fluorescence oscillated with a periodicity of 4, with a maximum after 2, and minimum after 4 flashes. A negligible oscillation wras observed in the absence of the electron transport mediators.
(4) When the prompt fluorescence intensity was measured under these conditions, a weak oscillation of period 4 with superimposed periodicity of 2 was observed in F0, but of insufficient amplitude to account for the observed changes of delayed fluorescence intensity in terms of the bade reaction caused by addition of DCMU.
(5) We therefore suggest that the enhancement of the delayed fluorescence is due to the release of protons accompanying transitions of the S-states, and that this release occurs not in synchrony with 02, but in all the transitions of the S-states with the exception of Si → S2 . We discuss the relative potentials of the transitions at the low internal pH which is generated as a result of cyclic electron transport around photosystem I in the conditions of our experiments.
Increase and Stabilization of Photoproduction of Hydrogen in Nostoc muscorum by Photosynthetic Electron Transport Inhibitors
Authors: Spiller Hartmut , Ernst Anneliese , Kerfin Wolfgang , Böger Peter 
Published: August 2018

Abstract
Nittrogen-fixing cells of Nostoc muscorum grown under nitrogen or in the presence of nitrate exhibit substantial light-induced hydrogen production for over 15 hours in the presence of electron transport inhibitors. Rates attain levels of 12 μmol H2 evolved/ml packed cell volume and hour. The ATP-dependent nitrogenase, not a hydrogenase, is responsible for hydrogen production. This is indicated by poor sensitivity to CO and inhibition of the reaction by uncouplers, acetylene, and N2 . An active uptake hydrogenase minimizes light-induced H2 production. Although nitrogenase activity is somewhat decreased by several photosynthetic electron transport inhibitors, hydrogen production is markedly increased. This is due to lowering the partial pressure of oxygen in the cell, preventing oxidative hydrogen consumption.
Alterations in Ecdysone Content during the Post-Embryonic Development of Chironomus thummi: Correlations with Chromosomal Puffing
Authors: Valentin M. , Bollenbacher W. E. , Gilbert L. I. , Kroeger H. 
Published: August 2018

Abstract
The ecdysone titer of larvae and pupae of Chironomus thummi was determined by radioimmune assay (RIA) and revealed a concentration of about 150 ng/g fresh weigth in late third instar larvae and a peak of more than 450 ng/g fresh weight just preceding pupation. The ecdysone titer curve shows a high degree of correlation with previously observed puffing activity at the ecdysone sensitive chromosomal site IIIdl. Further, β-ecdysone is the only endogenous ecdysone detected by high pressure liquid chromatography during larval-pupal development. It was also observed that developmentally arrested Chironomus contain less ecdysone than “normal” larvae.
Ribonuclease A Digestion by Proteinase K
Authors: Räuber Norbert R. K. , Jany Klaus-Dieter , Pfleiderer Gerhard 
Published: August 2018

Abstract
The digestion of ribonuclease A by proteinase K yielded one major degradation product only, which could not be distinguished from ribonuclease S by electrophoretical and immunological methods. This component (ribonuclease K) possessing full catalytic activity was characterized to be (1-20/211-124) ribonuclease A . Combined action of proteinase K and trypsin on ribonuclease A leads to a significant increase of the inactivation rate which may be useful in the isolation of mRNA from polysomes.
External Proton Uptake, Internal Proton Release and Internal pH Changes in Chromatophores from Rps. sphaeroides Following Single Turnover Flashes
Authors: Saphon Satham , Gräber Peter 
Published: August 2018

Abstract
The change in internal pH in chromatophores from Rps. sphaeroides following short flash ex­citation has been investigated using the method of the fluorescence quenching of 9-aminoacridine.
(1) A single turnover flash induced a fluorescence quenching of ≅ 0.4%. The fluorescence quenching was stimulated by valinomycin, and oligomycin, and inhibited by antimycin A.
(2) The extent of the pH gradient generated by a single turnover flash at the external pH ≅ 8 was estimated to be less than 0.4 unit.
(3) In a multiflash experiment the change in internal pH induced by each flash was found to be not linearly dependent on the number of protons which had been taken up after each flash from the external medium.
We discuss the significance of the results with respect to the mechanism of phosphorylation. The release of H+ taken up outside the chromatophore into the membrane could not be excluded by the present results.
The Incorporation of [1,2-13C2] Acetate into Pisatin to Establish the Biosynthesis of Its Polyketide Moiety
Authors: Stoessl A. , Stothers J. B. 
Published: August 2018

Abstract
The biosynthesis of the polyketide moiety in pisatin has been examined by incorporation experiments with [1,2-13C2] acetate and 13C-NMR measurements. The results establish that the C-5 carbonyl group in the enzyme-bound, open-chain polyketide precursor is reduced before cyclization to form the aryl ring. The specific incorporation attained in these experiments was considerably higher than that reported for earlier studies using singly labelled, radioactive acetate, emphasizing the importance of the timing of precursor addition.
Inhibition of Photosynthesis by Bentazon in Intact Plants and Isolated Cells in Relation to the pH
Authors: Retzlaff G. , Hilton J. L. , St. John J. B. 
Published: August 2018

Abstract
Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H)-one 2,2-dioxide] causes an increase in the chlorophyll fluorescence in the leaves of mustard plants [Smapis alba (L.) ] as a result of its in­hibitory effect on the photosynthetic electron transport. The rate of this fluorescence induction depends on the pH of the suspension medium. As the concentration of hydrogen ions diminishes, the maximum fluorescence that indicates a total inhibition of photosynthesis is reached at a later time.
In the case of single cells isolated from the leaves of soybean plants [Glycine max (L.) Mer “Harosoy”], bentazon inhibits photosynthetic CO1, assimilation. The amount of inhibition is depen­dent on the pH of the suspension medium. The uptake of CO2 is inhibited more at pH 6 than at pH 7 or 8. Bentazon is more readily absorbed by cells at pH 6 than at pH 7 or 8. The inhibition of CO2 assimilation is proportional to the amount of bentazon taken up.
Differential Effects of Herbicides upon Trypsin-Treated Chloroplasts
Authors: Böger Peter , Kunert Karl-Josef 
Published: August 2018

Abstract
With trypsin-treated spinach chloroplasts and the assay system H2O→ FeCy, photosynthetic electron transport inhibitors could be subdivided into four groups according to their different inhibitory behaviour under the conditions used.
1. Inhibition exerted by ureas, triazines, triazinones and pyridazinones was reversed to 50 - 60% as against the untreated control.
2. Inhibition by dibromothymoquinone, trifluralin or the 2,4-dinitrophenylether of 2-iodo-4-nitrothymol was almost completely reversed.
3. Inhibition caused by higher concentrations of nitrofen or the analog RH 2512 could only be reversed to a small extent.
4. Phenol herbicides showed increased inhibitory activity during short-term assays.
Site of Action and Quantitative Structure-Activity Relationship of a Series of Herbicidal N-Aryl-Substituted 3,4-Dimethyl-2-hydroxy-5-oxo-2,5-dihydro-pyrrolones
Authors: Brugnoni G. P. , Moser P. , Trebst A. 
Published: August 2018

Abstract
Substituted phenyl-hydroxy pyrrolone derivatives are potential herbicides and are found to be effective inhibitors of photosynthetic electron flow in chloroplasts. Their site of inhibition is localized at the acceptor side of photosystem II similar to DCMU. They have no effect on photophosphoryla­tion. The correlation of photosynthetic acitivity to chemical structure is studied by comparing 36 derivatives. A clear dependence of inhibitory activity on lipophilicity is found. The dependence of herbicidal activity on chemical structure is more complex.
On the Action of Chlorosis-Inducing Herbicides in Leaves
Authors: Feierabend Jürgen , Schulz Ulrike , Kemmerich Petra , Lowitz Theresia 
Published: August 2018

Abstract
The chlorosis induced by several different herbicides (group 1: aminotriazole, haloxidine; group 2: Sandoz 6706, difunon) in developing leaves of rye seedlings (Secale cereale L.) growing in light of 5,000 lx was, in addition to the absence of chlorophyll and carotenoids, accompanied by specific deficiencies of the 70 S ribosomes and of both chloroplastic and peroxisomal enzymes as previously described (Plant Physiol. 61, 1017 - 1022 (1978)) while growth and mitochondrial activities were little or not impaired.
In dim light (10 lx) chlorophyll was formed and the chloroplastic and peroxisomal enzymes reached activities comparable to those in untreated leaves at 10 lx. Upon exposure to 30,000 lx a rapid bleaching of existing chlorophyll and a rapid inactivation of the plastidic enzyme NADP-glyceraldehydephosphate dehydrogenase occured after treatment with herbicides of group 2 but not in the presence of herbicides of group 1. After all treatments catalase was rapidly inactivated after transfer to high light intensity. The bleaching of chlorophyll and the enzyme inactivations occurred also at 0 °C. In the herbicide-bleached leaves grown at 5,000 lx the in vivo synthesis of (δ-aminolevulinic acid was low and in the presence of Sandoz 6706 and difunon the capacity for protochlorophyll (ide) synthesis was largely inactivated.
Interference of ʟ-α-Aminooxy-β-Phenylpropionic Acid with Phenylalanine Metabolism in Buckwheat
Authors: Holländer Heike , Kiltz Hans-Hermann , Amrhein Nikolaus 
Published: August 2018

ʟ-α-Aminooxy-β-phenylpropionic acid (AOPP), a potent competitive inhibitor of phenylalanine ammonia-lyase (PAL), blocked light-induced phenylpropanoid synthesis in excised buckwheat hypocotyls and produced an up to 40-fold increase in the endogenous phenylalanine concentra­tion, while the level of all other amino acids was hardly affected.
After a 24 h incubation in the light in the presence of 0.3 or 1 mᴍ AOPP phenylalanine alone constituted about 25% of the total soluble amino acids, compared to appr. 1% in the controls.
In the presence of AOPP illuminated hypocotyls accumulated nearly 3 times more phenylala­nine than hypocotyls kept in the dark, indicating an enhancing effect of light on the flow of carbon through the shikimate pathway. Exogenously added [14C] phenylalanine was extensively metab­olized by control tissue, but accumulated in AOPP treated tissue. In the presence of AOPP radio­activity from [14C] shikimate accumulated predominantly in phenylalanine, and the flow of shi­kimate into tyrosine and phenylalanine was not affected by the inhibitor. Therefore, under these conditions no feedback control of phenylalanine and tyrosine synthesis from shikimate is apparent in buckwheat hypocotyls.
New C30-Carotenoic Acid Glucosyl Esters from Pseudomonas rhodos
Authors: Kleinig Hans , Schmitt Rüdiger , Meister Walter , Englert Gerhard , Thommen Hans 
Published: August 2018

Abstract
The carotenoid pigments of the Gram-negative bacterium Pseudomonas rhodos were identified as 4,4′-diapocarotene-4-oic acid, di (β,ᴅ-glucosyl) 4,4′-diaptocarotene-4,4′-dioate, and β,ᴅ-glucosyl-4,4′-diapocarotene-4-oate-4′-oic acid. One hydroxy group of the glucose moieties, probably at C (6), was esterified with one of several fatty acids (12:0, 14:0, 14:1, 16:0, 1 6 :1).
A PAPS-Dependent Sulfotransferase in Cyanophora paradoxa Inhibited by 5ʹ-AMP, 5ʹ-ADP, and APS
Authors: Schmidt Ahlert , Christen Ursula 
Published: August 2018

Abstract
A 3′-phosphoadenosine-5′-phosphosulfate (PAPS) dependent sulfotransferase was partly purified from Cyanophora paradoxa. This enzyme has a pH-optimum of 8.5 and was found to be specific for PAPS ; the Km for this nucleotide was determined to be 8.3 μᴍ. In crude extracts monothiols like glutathione, mercaptoethanol, or cysteine catalyzed a rate of about 80% of the rate obtained with dithioerythritol; however after purification of the PAPS-sulfotransferase the monothiol activity decreased to about 20% of the rate obtained with dithiols. Addition of heated, crude extract partly restored the monothiol activity. This PAPS-sulfotransferase was inhibited by 5′-ADP and 5′-AMP, and especially by adenosine-5′-phosphosulfate (APS). Practically no inhibition was found with 2′-AMP, 3′-AMP, c-AMP, 3′-5′-ADP and 2′-5′-ADP. The inhibitor constants have been determined to be 430 μᴍ for 5′-AMP; 290 μᴍ for 5′-ADP; and 0.3 μᴍ for APS. These inhibitions seem to be competetive to PAPS. The role of these inhibitors for a possible regulation of assimilatory sulfate reduction are discussed.
Density-Dependent Growth Inhibiting Interactions between 3T3 and SV40-3T3 Cells in Mixed Cultures
Authors: Bosch Jürgen van der , Maier Heinz 
Published: August 2018

Abstract
3T3 cells are shown to reduce SV40-3T3 cell population growth in a density-dependent manner in co-cultures of 3T3 and SV40-3T3 cells. The development of this inhibitory activity roughly parallels the development of density-dependent inhibition of growth in homogeneous 3T3 control cultures. The extent of reduction of SV40-3T3 growth can be manipulated by pretreatment of 3T3 cells with a high serum concentration. SV40-3T3 growth rates are reduced by factors between 10 and 20 under optimum inhibitory conditions as compared to SV40-3T3 growth in control cultures.
Notizen: Phytoalexin Production by Flowers of Garden Pea (Pisum sativum )
Authors: Ingham John L. 
Published: August 2018

Abstract
The isoflavonoid phytoalexin pisatin has been isolated from fungus-inoculated petals of 16 Pisum sativum cultivars. Pisatin was usually accompanied by trace quantities of maackiain. No other fungitoxic compounds were detected.
Hastatosid, ein neues Iridoid aus Verbena hastata L. und Verbena officinalis L. [1] / Hastatoside, a New Iridoid from Verbena hastata L. and Verbena officinalis L. [1]
Authors: Rimpler Horst , Schäfer Bernd 
Published: August 2018

Abstract
Verbenalin and a new iridoid, hastatoside (2) have been isolated from Verbena hastata and V. officinalis. The structure and absolute configuration of hastatoside has been determined by spectroscopical methods, and by correlating 2 chemically with verbenaline and the lactone 6. The lactone 7 has been synthesized from verbenaline. The name brasoside-tetraacetate is proposed for 7, since brasoside has been found in V. brasiliensis as a natural product.
A 1H NMR Study of the Syn-Anti Dynamic Equilibrium in Adenine Nucleosides and Nucleotides with the Aid of Some Synthetic Model Analogues with Fixed Conformations
Authors: Dudycz Lech , Stolarski Ryszard , Pless Reynaldo , Shugar David 
Published: August 2018

Abstract
The syn-anti equilibrium about the glycosidic bond in adenosine and some related analogues was studied by means of 1H NMR spectroscopy, with the aid of several model analogues fixed in given conformations either by intramolecular bonding, or by introduction of a bulky substituent. A model unambiguously and exclusively in the syn conformation is 8-(α-hydroxyisopropyl) adenosine; while one fixed in the a n ti conformation is 8,5′-anhydro-8-oxoadenosine. A new analogue, fixed in the high an ti conformation, is 8,2′-O-isopropylidenearabinofuranosyladenine. Several additional new model compounds were synthesized and their properties are described.
With the aid of these models, the syn-anti dynamic equilibrium was examined for adenosine and some related compounds in different solvent systems, and the conformer populations evaluated quantitatively. The validity of the procedure applied, and the accuracy of the results, are critically examined, and compared with findings obtained by other procedures. Available literature data on the syn-anti equilibrium in other 8-substituted adenosines are re analyzed in the light of the present results. An analysis is also presented of the interdependence of the various conformational parameters, i. e. conformation about the glycosidic bond and those of the sugar ring and exocyclic carbinol group, in adenosine and 2′,3′-O-isopropylideneadenosine.
Comparative Studies on the Dodecameric and Hexameric Forms of Yeast Aminopeptidase I
Authors: Löffler H.-G. , Rohm K.-H. 
Published: August 2018

Abstract
Yeast Aminopeptidase I, Molecular Forms, Immunological Behaviour Yeast aminopeptidase I, when purified from autolysates of brewer’s yeast, is obtained in two molecular forms a) the enzymatically active dodecameric complex (Mr = 640 000, s20, w = 22 S) and b) inactive hexamers (Mr = 320 000, s20, w = 12 S). Although the amino acid composition of the 12 S protein is very similar to that of the active enzyme, the hexamers behave differently in ionic exchange chromatography and during electrophoresis on polyacrylamide gels. Moreover, the antigenic properties of 12 S and 22 S aminopeptidase forms suggest a considerable degree of structural diversity. Several strains of Saccharomyces cerevisiae did not contain hexameric forms although their 22 S aminopeptidase was immunologically indistinguishable from brewer’s yeast amino­ peptidase. It is proposed that the hexameric protein is the result of “unproductive ” aggregation of aminopeptidase subunits.
Drug-Protein Interaction: 8-Methoxy Psoralen as Photosensitizer of Enzymes and Amino Acids
Authors: Veronese F. M. , Schiavon O. , Bevilacqua R. , Rodighiero G. 
Published: August 2018

Abstract
For a better insight of the molecular basis of the photobiological effects of furocoumarins, the relevance of proteins oxydation by singlet oxygen produced by these substrates under irradiation with long u. v. light was studied.
Complex oligomeric as well as simple monomeric purified enzymes with high or low molecular weight and different properties and simple amino acids were irradiated under oxygen in presence of 8-methoxy-psoralen. The effects on both proteins and amino acids were compared with those obtained under similar conditions with typical photosensitizers as methylene blue and Rose Bengal. The results indicated that the photooxydation of proteins, although possible, appears to play a minor role, if any, in the mechanism of action of furocoumarin.
On the Possible Involvement of Ascorbic Acid and Copper Proteins in Leukemia. III. ESR Investigations on the Interaction between Ascorbic Acid and Some Transition Metal Ions
Authors: Lohmann Wolfgang , Lange Rainer 
Published: August 2018

Abstract
The interaction between lyophilized samples of ascorbic acid and Cu2+, Fe3+ or Mn2+ has been investigated by means of ESR spectroscopy. All of the three transition metal ions form complexes with vitamin C, but only in the case of Cu2+ and Fe3+ the interaction results in a reduction of the metal ions. Cu2+ and ascorbic acid seem to form 2 : 1 complexes with an equilibrium constant of about K = 1 x 107 mol-1. None of these metal ion complexes exhibits, however, the ESR spectrum obtained with leukemic blood.