bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulphite as Intermediate Sulphur Compound in Anaerobic Sulphide Oxidation to Thiosulphate by Marine Cyanobacteria
Authors: Rabenstein Andreas , Rethmeier Jörg , Fischer Ulrich 
Published: August 2018

Abstract
Anaerobic sulphide oxidation in the light was studied with seven cyanobacterial strains isolated from the southern Baltic Sea. All strains oxidized sulphide (1.2-3.5 mM) stoichio-metrically to thiosulphate. No elemental sulphur could be detected as end product of anoxy-genic photosynthesis. Sulphite as intermediate sulphur compound was released into the growth medium during anaerobic sulphide oxidation by these cyanobacteria. The formation of sulphite from sulphide was inhibited by the photosynthesis inhibitor DCMU.
The cyanobacterium Oscillatoria sp. strain BO 32 produced another so far not identified intermediate sulphur compound which was probably stored within the cells.
Consequences of High CO2-Concentrations in Air on Growth and Gas-Exchange Rates in Tobacco Mutants
Authors: He P , Bader K. P , Radunz A , Schmid G.H 
Published: August 2018

Abstract
Wild type tobacco N. tabacum var. John William’s Broadleaf and the tobacco aurea mutant Su/su were permanently grown under 700 ppm CO2 in air. In comparison to plants grown under 350 ppm CO2 in air but under otherwise identical conditions growth was substantially enhanced. Gas exchange measurements carried out by mass spectrometry show that the rate of photosynthesis in the wild type and in the mutant is increased by more than 100%. The photorespiratory rate in the wild type measured as 18O2-uptake in the light in the “700 ppm CO2-plants” is not reduced to the extent expected or deduced from experiments in which the 350 ppm system responds under in vitro conditions to 700 ppm CO2. An analysis of the induction kinetics of room temperature fluorescence kinetics of the adapted (700 ppm CO2) system and the control system (350 ppm CO2) under various CO2-partial pressures shows that permanent growth under the elevated CO2-partial pressure leads to a structural modification of the photosynthetic apparatus.
Quantification of Ecdysteroids by Immunoassay: Comparison of Enzyme Immunoassay and Radioimmunoassay
Authors: Pascual Nuria , Bellés Xavier , Delbecque Jean-Paul , Hua Yue-Jin , Koolmanc Jan 
Published: August 2018

Abstract
The performance of enzyme immunoassay (EIA) and radioimmunoassay (RIA) in the quantitative analysis of ecdysteroids was compared. The EIA was found to be at least equivalent to the RIA with respect to analytical range and sensitivity and to be more comfortable with respect to safety and time saving. When biological samples were analyzed by both assays a good correlation (r = 0.83) was found. Since the EIA has certain advantages over the RIA, we now recommend the use of the former assay for the quantification of ecdysteroids.
Comparison on Reactivity of Fe(III) and AI(III) Compounds in the Presence of Hydrogen Peroxide: Its Relevance to Possible Origin for Central Nervous System Toxicity by Aluminum Ion
Authors: Nishida Yuzo , Ito Sayo 
Published: August 2018

Abstract
The iron(III) compounds with several aminocarboxylate chelates containing an aryl or furan substituent exhibit high activity in enhancement of the reactivity of hydrogen peroxide, leading to facile hydroxylation at benzene ring, and to degradation of furan ring, but no such activity was observed for the corresponding Al(III) compounds. These results were inter­preted in terms of the molecular orbital consideration, and lack of the activity of the Al(III) complexes was attributed to lack of electrophilic nature of the peroxide adduct due to the absence of a d-orbital: this may explain the fact that there were no tumors in Al-NTA (nitrilotriacetic acid)-treated rats. Based on the facts observed in this study, the decreased function of iron(III) ions for synthesizing neurotransmitters in the brain was assumed to be one of the possible origin for the neurotoxicity by injection of the Al(III) salts in vivo.
Caffeine Metabolism in High and Low Caffeine Containing Cultivars of Camellia sinensis
Authors: Ashihara Hiroshi , Shimizu Hisayo , Takeda Yoshiyuki , Suzuki Takeo , Gillies Fiona M. , Crozier Alan 
Published: August 2018

Abstract
The metabolism of [8-14C ]adenine and [2-14C]caffeine was examined in leaf segments from flush shoots of tea cultivars with high and low caffeine content. The caffeine biosynthesis pathway from AMP via theobromine was operative in both high and low caffeine containing cultivars. There was a m ore rapid rate of caffeine biosynthesis from [8-14C ]adenine in the high caffeine cultivars while the rate of degradation of both adenine nucleotides and caffeine into CO2 was greatest in cultivars with a low endogenous caffeine content. Cell-free p reparations from tea shoots contained an N-methyltransferase, that is a keyenzyme in the caffeine biosynthesis pathway; more in-vitro activity was detected in preparations from high caffeine containing cultivars. The data obtained suggest that the high caffeine containing cultivars have a more rapid rate of caffeine biosynthesis and a slower rate of caffeine catabolism than cultivars with a low endogenous caffeine content
Homocysteine-Induced Oxidative Damage: Mechanisms and Possible Roles in Neurodegenerative and Atherogenic Processes
Authors: Schlüssel Elke , Preibisch Gudrun , Piitter S. , Elstner E. F. 
Published: August 2018

Abstract
Increased blood plasma concentrations of the sulphur amino acid homocysteine (“homocysteinemia”) have been brought into context with neurodegenerative and arteriosclerotic symptoms and diseases.
We recently reported on biochemical model reactions on the prooxidative activity of hom ocysteine including the desactivation of Na+/K+-ATPases and hemolysis of erythrocytes (Preibisch et al., 1993). In this communication we extend our model reactions including the oxidation of methionine, metabolization of pyridoxalphosphate and dihydroxyphenylalanine, desactivations of transaminases and peroxidation of low density lipoprotein
Evidence of Surface Diffusion of Water Molecules on Proteins of Rabbit Lens by NMR Relaxation Measurements
Authors: Bodurka Jerzy , Buntkowsky Gerd , Gutsze Aleksander 
Published: August 2018

Abstract
In this work, we propose a relaxation model for the interpretation of NMR proton spinlattice and spin-spin relaxation times of mammalian lenses. The framework for this model is based on nuclear magnetic spin-lattice relaxation measurements as a function of tem perature at different Larmor frequencies for whole rabbit lenses and fragments of the lens. According to this model, two different dynamic processes of the water molecules determine the relaxation behaviour, namely rotational diffusion and translational surface diffusion. These dynamic processes in conjuction with a two site exchange model give a good explanation of all the measured relaxation data. From the experimental data, we were able to obtain the activation parameters for rotational and translational diffusion of bound lens water. Correlation times of 2.1×10-11 sec and 2.5×10-9 sec and activation energies of 20.5 kJ/mol and 22.5 kJ/mol respectively were found at 308K. At low Larmor frequencies (≤ MHz) the longitudinal relaxation is mainly determined by translational surface diffusion of bound water with a mean square displacement of 1.5 nm, whereas at higher frequencies (≥300 MHz), rotational diffusion is the main relaxation mechanism. The spin-spin relaxation is determined by translational diffusion over the whole frequency range and therefore shows only a very small dispersion. By our model it is possible to explain: 1) the strikingly large difference between the T1 value and the T2A and T2B values observed in the lens and 2 ) the different values of the activation energies measured at different fields for the lens.
Effect of 2'-Deoxyguanosine Oxidation at C 8 Position on N-Glycosidic Bond Stability
Authors: Bialkowski Karol , Cysewsk Piotr , Olinski Ryszard 
Published: August 2018

Abstract
8-Oxo-2′-deoxyguanosine, 8-Oxoguanine, 8 -Hydroxyguanine, Base Modification, DNA Oxidative Damage The influence of 2′-deoxyguanosine (dG) oxidation at the C-8 position on N-glycosidic bond stability was in­ vestigated. A kinetic analysis of dG and 8-oxo-2′-deoxy-guanosine (8-oxodG) depurination reactions was carried out in water solutions at pH ranging from 2 to 7.4 and temperature of 100 °C. The results indicate that N-glyco­ sidic bond of 8-oxodG is significantly more stable in comparison with dG at any pH applied. At pH 5.1 hy­drolysis rate of dG is 4.5-fold higher than that for 8-oxodG. The chemical stability of the modified nucleo­ side in oxidatively damaged DNA is one of important factors contributing to its mutagenic potential. Results of our experiments indicate that 8-oxodG, potentially mutagenic and carcinogenic nucleoside, is hardly suscep tible to spontaneous depurination and its removal from cellular DNA depends mostly on the activity of DNA repair enzymes.
GC Profiles of Volatile Constituents from Human Urine Obtained by Closed Loop Stripping, Purge and Trap Technique and Simultaneous Steam Distillation-Extraction
Authors: Bestmann Hans Jürgen , Haberkorn Klaus , Vostrowsky Otto , Ferstl Roman , Eggert Frank 
Published: August 2018

Abstract
Different techniques like “closed loop stripping” [CLSA], “purge and trap” [PTI], and continous steam distillation extraction [SDE] were used to establish GC profiles of major histocompatibility complex-associated volatile constituents of human urine and statistically evaluated for reliability. Of the three methods investigated, PTI appeared to be superior for the detection of very volatile substances, whereas SDE was the most efficient one with respect to yield. A number of short to medium-chain ketones, 4-hydroxy-3-methoxy-styrene, menthol and nicotine were identified in preliminary analyses.
Lipids Associated with the (Na+-K+)ATPase Activity of Normal and Denervated Electric Organs of Electrophorus electricus (L.)
Authors: Barriviera M. L , Hasson-Voloch A 
Published: August 2018

Abstract
The effect of denervation on the lipid metabolism and on the activity of (Na+-K+)ATPase isoforms from the membrane fraction P3, which corresponds to the innervated electrocyte membrane, was evaluated. On a discontinuous sucrose gradient, normal P3 membranes exhibit a bimodal (“a” and “b ” bands) distribution of the (Na+-K+)ATPase activity, which upon denervation changes to an unimodal (“c” band) distribution. Using these fractions, which have a higher (Na+-K+)ATPase activity, we characterized the lipids at the hydrophobic protein surface boundary, (i.e., the bulk lipids that surround the protein). The results confirm that these lipids consist of phospholipids and cholesterol. The quantitative composition of the phospholipids is similar for both isoform fractions obtained from the discontinuous gradient of normal membranes, with phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine representing about 90% of the total phospholipids. Sphingomyelin, phosphatidylinositol, diphosphatidylglycerol and phosphatidic acid were in the minority. However, in the single band obtained after denervation, the three major phospholipid components decreased to 70% of the total, and a significant increase in the other phospholipids and in cholesterol was observed. The high cholesterol content of the denervated fraction may confer membrane stabilization, as it is likely to cause a decrease in the membrane fluidity and consequently in the enzyme activity.
24-Epibrassinolide from Gypsophila perfoliata
Authors: Schmidt Jürgen , Böhme Frank , Adam Günter 
Published: August 2018

Abstract
The scarce 24-epibrassinolide could be identified from seeds of Gypsophila perfoliata L. by GC/MS as the only brassinosteroid present. Furthermore, the Δ7-phyto-sterols ergost-7-en-3β-ol, spinasterol and 22-dihydro-spinasterol were found as main sterols in the same plant material.
A Cytotoxic Principle of Tamarindus indica, Di-w-butyl Malate and the Structure-Activity Relationship of Its Analogues
Authors: Kobayashi Akio , Adenarr Mohd Ilham , Kajiyama Shin-ichiro , Kanzaki Hiroshi , Kawazu Kazuyoshi 
Published: August 2018

Abstract
Bioassay-guided fractionation of the methanolic extract of Tamarindus indica fruits led to the isolation of L -(-)-di-nbutyl malate which exhibited a pronounced cytotoxic activity against sea urchin embryo cells. In order to study structure-activity relationships, close-structure relatives of di-n-butyl malate were synthesized using d -(+) -and L -(-)-malic acid as starting materials, and their cytotoxic activities were exam in ed for the sea urchin em bryo assay. L -(-)-D i-n-pentyl malate was the most effective inhibitor to the development of the fertilized eggs. Significant inhibitory activity was not seen in the esters of D -(-)-isomer .
Conformational Changes Involved in the Switch from Ovalbumin to S-Ovalbumin
Authors: Castellano Agostina Congiu , Barteri Mario , Bianconi Antonio , Bruni Fabio 
Published: August 2018

Abstract
For the first time a comparative study on conformational differences between native oval­ buminand its heat-stable form, called S-ovalbumin. using small angle x-ray scattering, is reported. To detect a different pathway in the folding mechanism of the two proteins, scatter­ing measurements have been performed on ovalbumin and S-ovalbumin denatured with dif­ferent concentrations of guanidine hydrochloride, and by heating the proteins at acid pH. The intensity scattering curves provide evidence that the intermediate states in the unfolding process are globular for both proteins while their compactness changes. The reported experi­mental results suggest that the ovalbumin to S-ovalbumin transformation can be considered a protein-switch triggered by changes in the chemical conditions of the protein environment. Because the conformational changes are likely to be of functional importance, we infer that the occurrence in vivo of S-ovalbumin is thus determined by the transformation of ovalbumin, with a functional role for embryonic development, into a new protein with a dif­ferent function.
Altered Fatty Acid, Cholesterol and Na+/K+ ATPase Activity in Erythrocyte Membrane of Rheumatoid Arthritis Patients
Authors: Masoom-Yasinzai M. 
Published: August 2018

Abstract
Rheumatoid Arthritis, Cholesterol, Eicosapentaenoic Acid. Na+/K+ ATPase, Erythrocyte Membrane Rheumatoid arthritis (RA) is a chronic inflamatory disease whose cause remains obscure. Blood from 15 R A patients and controls was taken and their ghosts separated. The ghosts were analysed for cholesterol content, Na+/K+ ATPase activity and eicosapentaenoic acid. The cholesterol content in the ghosts of RA patients was significantly lower as compared with the set of controls. There was a major difference in the activity of Na+/K+ ATPase between the two groups with RA patients showing significantly elevatad activity. The ghosts of the RA patients exhibited major abnormality in the polyunsaturated fatty acids of phos­pholipids with the level of eicosapentaenoic acid (ω-3, 20:5) being significantly reduced.
Aspects of the Cell Growth of Candida guilliermondii in Sugar Cane Bagasse Hydrolysate
Authors: Molwitz M. , Silva S.S. , Ribeiro J.D. , Roberto I.C. , Felipe M.G.A. , Prata A.M.R. , Mancilha I.M. 
Published: August 2018

Abstract
In this work the behavior of the growth of Candida guilliermondii FTI 20037 in sugar cane bagasse hemicellulosic hydrolysate on various oxygen transfer rates was investigated. The yeast was able to grow and produced xylitol at different performence levels. At 1.0 vvm (volume of air per volume of medium per minute) the highest growth with 24.4 g/g was observed, but no xylitol was produced. At aeration rate of 0.5 vvm the growth was lower, but therefore slight amounts of xylitol (xylitol yield factor - Yp/s = 0.15 g/g) were observed. The lowest cell concentration (10.7 g/l) and the highest xylitol yield (Yp/s = 0.46 g/g) was observed when aeration was changed from 0.5 vvm to 0.05 vvm after 14 h.
Diadenosine 5′,5‴- P1,P4-tetraphosphate (Ap4A) Hydrolase from Tomato (Lycopersicon esculentum cv. Lukullus) -Purification, Biochemical Properties and Behaviour during Stress
Authors: Feussner Kirstin , Guranowski Andrzej , Kostka Susanne , Wasternack Claus 
Published: August 2018

Abstract
Dinucleoside 5′,5‴-P1,P4-tetraphosphate hydrolase (EC 3.6.1.17) has been purified to homogeneity from tomato (Lycopersicon esculentum) cells grown in suspension. The purification procedure comprised ammonium sulphate fractionation following five standard chroma­ tography steps and a final chromatography on Ap4A-Sepharose.
The homogeneous hydrolase has a molecular mass of 20 kD a and an isoelectric point of 4.5. The enzyme hydrolyses diadenosine tetraphosphate (Ap4A) asymmetrically to AMP and ATP. Among other naturally occurring dinucleoside oligophosphates, Ap5A and Ap6A are substrates whereas Ap3A is not. Of various phosphonate analogues tested, the Ap5A analogue, AppCH2pCH2ppA, was not cleaved and the Ap3A analogue, ApCH2CH2ppA. was a very poor substrate. Enzyme activity is stimulated by 5mм Mg2+ and inhibited by fluoride anion; I50 = 6.25 μм . The Km value for Ap4A is 0.8 μм . The enzyme exhibits a broad pH optimum from pH 6.5 to 9.0. In order to analyze the protein at the molecular level an internal peptide sequence from the homogeneous enzyme was identified. Within the sequence of 17 amino acids a kinase II motif as a general part of a conserved sequence of nucleotide binding sites was found.
Against the internal peptide sequence a polyclonal antiserum was raised. By investigating the intracellular level of Ap4A hydrolase under different kinds of environmental stress, no changes occurred in response to heat shock. But, heavy metal stress and phosphate deprivation lead to a decrease in Ap4A hydrolase.
Ca2+ Uptake Coupled to Glycogen Phosphorolysis in the Glycogenolytic-Sarcoplasmic Reticulum Complex from Rat Skeletal Muscle
Authors: Nogues M. , Cuenda A. , Henao F. , Gutiérrez-Merino C. 
Published: August 2018

Abstract
The glycogenolytic-sarcoplasmic reticulum complex from rat skeletal muscle accumulates Ca2+ upon stimulation of glycogen phosphorolysis in the absence of added ATP. It is shown that an efficient Ca2+ uptake involves the sequential action of glycogen phosphorylase, phosphoglucomutase and hexokinase, which generate low concentrations of ATP (approximately 1 -2 μм) compartmentalized in the immediate vicinity of the sarcoplasmic reticulum Ca2+, Mg2+-ATPase (the Ca2+ pump). The Ca2+ uptake supported by glycogenolysis in this subcellular structure is strongly stimulated by micromolar concentrations of AMP, showing that the glycogen phosphorylase associated with this complex is in the dephosphorylated b form. The results point out that the flux through this compartmentalized metabolic pathway should be enhanced in physiological conditions leading to increased AMP concentrations in the sarcoplasm, such as long-lasting contractions and in ischemic muscle.
Non-Enzymatic, Low Temperature Fluorescence in situ Hybridization of Human Chromosomes with a Repetitive α-Satellite Probe
Authors: Durm Markus , Haar Frank-Martin , Hausmann Michael , Ludwig Horst , Cremer Christoph 
Published: August 2018

Abstract
In all DNA-DNA in situ hybridization (ISH) procedures described so far in the literature, the production of single-stranded target DNA sequences plays a decisive role. This can be achieved either by enzymatic treatment at physiological temperatures or by the separation of double-stranded DNA sequences. Denaturation by heat and chemical agents (e.g. formamide) is regarded as a prerequisite for the non-enzymatic ISH process. However, additional mechanisms of a non-enzymatic ISH procedure are conceivable which do not require high temperature treatment combined with formamide. Here, we report on a non-enzymatic, non-formamide, low temperature, fluorescence in situ hybridization (FISH) procedure which allowed a microscopic visualization and quantitative fluorescence analysis of the binding sites of a repetitive DNA probe. Following only probe denaturation at 94 °C, hybridization was performed at 52 °C for 30 min, i.e., at nearly physiological temperatures. Moreover, increasing the hybridization time to 3 hours indicated that hybridization sites became also visible at 37 °C. Since the protocols are based on recently described Fast FISH developments, the technique will be called Low Temperature Fast-FISH (LTFF).
A Visually Induced Switch in Mode of Locomotion of a Spider
Authors: Schmid Axel 
Published: August 2018

Abstract
The spider Cupiennius salei Keys. (Araneae, Ctenidae) is a nocturnal hunter living on monocotyledones. It does not build webs for prey capture. During the day it remains in its retreat and during dusk it begins to hunt for prey or to search for mates. C. salei is well equipped with mechanosensory systems to detect air- or substrate- borne vibrations elicited by prey or predators. If none of them produce either air movements or substrate vibrations, and the light intensity is below the threshold (0.1 lx), the animal is virtually " blind" . There­ fore a hypothetical, additional sensory input should exist, which is used only in complete darkness. The animal was tested on a locomotion compensator were it performs constant walks towards a visual target. Three different light intensities were used (bright 200 lx, dim 0.1 lx, and dark at 950 nm, which is outside the spectral sensitivity range of the animal). At bright and dim illumination the animal walked in the alternating tetrapod gait towards the target. In complete " darkness" the walk was no longer directed and the animal changed its gait and continued walking on only six legs using the first pair as guide-sticks. If the first pair is missing, the second cannot replace this function. This shows a twofold use of the first pair o f legs as ordinary walking legs and as guide-sticks or " antennae" . Therefore one can assume that visual input causes a behavioral change, which can not be explained by a fixed locomotion pattern but by adaptive changes caused by visual inputs.
Induction of Hydroxycinnamoyl-CoA: Hydroxyanthranilate N-Hydroxycinnamoyl- transferase (HHT) Activity in Oat Leaves by Victorin C
Authors: Ishihara Atsushi , Matsukawa Tetsuya , Miyagawa Hisashi , Ueno Tamio , Mayama Shigeyuki 
Published: August 2018

Abstract
Victorin C, a host-specific toxin produced by Helm inthosporium victoriae, induced hydro-xycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyltransferase (HHT, EC 2.3.1) ac­tivity in oat leaves (Avena sativa L., a cultivar carrying Pc-2 gene). This enzyme activity catalyzes the final step of biosynthesis of oat phytoalexins, avenanthramides. The HHT activ­ity was detected after 12 h of victorin C application and reached to a maximum by 18 h. The induction of HHT was dose-dependent. All of the putative precursors of avenanthramides acted as substrates for HHT. These findings indicate that the accumulation of avenanthram ­ ides by victorin C treatment is due to induction of HHT. The enzyme activity showed highest specificity to 5-hydroxyanthranilate for the anthranyl moiety, while feruloyl-CoA was most effective for cinnamoyl moiety. HHT induced by victorin C showed significantly lower affinity for anthranilic acid relative to the enzyme induced by oligo-N-acetylchitooligosaccharides, another elicitor, suggesting that isozymes of HHT occur in this plant.
4-Pentadecylpyridine: A Competitive Polyphenoloxidase Inhibitor
Authors: Fuchs Claus T. , Spiteller Gerhard 
Published: August 2018

Abstract
4-Pentadecylpyridine was isolated from plums infected by Taphrina pruni. This fungal metabolite has been tested for its effect on polyphenoloxidase, using the polyphenoloxidase-catalysed addition of L-proline to 4-methylcatechol in a chromogenic assay The resulting data prove that 4-pentadecylpyridine is a competitive inhibitor to polyphenoloxidase with an inhibitor constant of 3.70 ± 0.03×10-4 м . Further comparative measurements have demon­strated that the effect is due to the pyridine moiety. Probably reduced polyphenoloxidase-activity decreases the toxicity of o-diphenols to the fungus and thus increases susceptibility of plums to the fungus Taphrina pruni.