bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperation of Compartments for the Generation of Positional Information
Authors: Meinhardt Hans 
Published: August 2018

Abstract
A mechanism is proposed for pattern formation in developmental subfields. In application to imaginal disks, the compartmentalization appears as a prerequisite for the generation of positional information in the proximo-distal dimension. Cooperation of three or four compartments in the production of a morphogen leads to a cone-shaped morphogen distribution, since a high production rate of the morphogen is possible only at the intersection of compartment borders. The local concentration of the cone-shaped distribution is a measure for the distance from this center and can be used as positional information. In agreement with the experimental observations, the model predicts that (i) the distalmost structures are formed at the intersection of compartment borders; (ii) distal transformation occurs whenever cells of all compartments come close to each other; (iii) distal transformation does not require a complete set of circumferential structures; (iv) mutants exist in which the positional information and not the response of the cells is altered and (v) no distal to proximal intercalation of missing leg segments occur. Regeneration and formation of supernumerary insect legs can be explained as well. Simple molecular reaction can account for this type of pattern formation. The “complete circle rule” of French, Bryant and Bryant (Science 193,969-981 (1976)) for distal transformation may be simplified by a “cooperation of compartments” rule.
The Oocytes of the Goby Pomatoschistus minutus. III. Determination of Amino Acid Component
Authors: Riehl Rüdiger 
Published: August 2018

Abstract
The oocytes of the marine goby Pomatoschistus minutus were analyzed for their amino acid content. Most of the amino acids exist as protein, only a little part is free or peptide-bound. Among the protein-bound amino acids, high levels of glutamic acid, proline, alanine, aspartic acid, valine and leucine were detected. These represent more than 60% of the protein amino acids. Among the free acids, glutamic acid, serine and alanine, are dominant. There are no certain proofs of the occurrence of peptide pools in the oocytes of Pomatoschistus minutus.
The Development of the Static Vestibulo-Ocular Reflex in Xenopus
Authors: Lang Hans-Georg , Horn Eberhard 
Published: August 2018

Abstract
The relation between the amount of the static vestibulo-ocular reflex arc and the developmental stage is characterized by an optimum function. The reflexes occur before the labyrinth is completely developed, but at this time, bilateral connections of the labyrinth with the oculomotor centers are efficient.
Sparticarpin: A Pterocarpan Phytoalexin from Spartium junceum
Authors: Ingham John L. , Dewick Paul M. 
Published: August 2018

Abstract
A new phytoalexin isolated from the fungus-inoculated leaflets of Spartium junceum (Spanish broom) has been identified as (-)-6 aR; 11 aR-2,3-dimethoxy-9-hydroxypterocarpan (sparticarpin). The total synthesis of sparticarpin is described.
Phenylpropanoic Acid Esters in the Essential Oil of Cistus ladanifer L. (Cistaceae)
Authors: Budzikiewicz Herbert , Proksch Peter , Gülz Paul-Gerhard 
Published: August 2018

Abstract
Esters of phenylpropanoic acid with 2-phenyl-ethanol-1 and the homologue, 3-phenyl-propanol-1 as well as geraniol and dehydrogeraniol were found in the essential oil of Cistus ladanifer. The isolation of these esters by chromatographic methods and structural elucidation by NMR and MS are described.
Enzymatic Synthesis of 1-Sinapoylglucose from Free Sinapic Acid and UDP-Glucose by a Cell-Free System from Raphanus sativus Seedlings
Authors: Strack Dieter 
Published: August 2018

Abstract
Protein extracts from seedlings of Raphanus sativus catalyze the transfer of the glucosyl moiety of UDP-glucose to the carboxyl group of phenolic acids. Enzymatic activity was determined spectrophotometrically by measuring the increase in absorbance at 360 nm and/or by the aid of high performance liquid chromatography (HPLC).
From 12 phenolic acids tested as acceptors, sinapic acid was by far the best substrate. The glucosyltransfer to sinapic acid has a pH optimum near 7 and requires as SH group for activity, p-Chloromercuribenzoate (PCMB) inhibits activity, which can be restored by the addition of dithiothreitol (DTT). The formation of 1-sinapoylglucose was found to be a reversible reaction, since the addition of UDP results in a breakdown of the ester.
Ruthenium Red Staining of Chromatin in Epon Sections
Authors: Stockert Juan C. , Paniagua R. 
Published: August 2018

Abstract
After staining with a 50% ethanol solution of ruthenium red, chromatin from onion and mouse cells showed red color and high contrast in the light and electron micro­scope, respectively. When applied to glutaraldehyde-fixed, Epon-embedded tissues, this selective staining technique proved to be dependent on the DNA content of chromatin.
Probable Phase Composition of the Mineral in Bone
Authors: Driessens F. C. M. 
Published: August 2018

Abstract
Formulas proposed for the mineral of bone were reviewed. Literature data were collected where Ca, P, Na, Mg and CO3 are determined in the same samples. These data were analyzed for their conformity to the above mentioned formulas. According to this analysis Mg is contained in a phase having the Ca/P of magnesium whitlockite within the limits of error. Na is contained in a carbonated calcium phosphate phase which in analogy with synthetic systems must have the apatite structure. The Ca/P ratio of the remaining "rest phase" is 2. This is based on the composi­ tion of 101 bone mineral samples taken from fishes, reptiles, amphibians, birds and mammals. The CO3 content of the bone samples agrees with the formula
Ca8 (PO4)4 (CO3) (OH)2 · x H2O
for the "rest phase" within the limits of experimental error. Such a compound has, however, not been found in synthetic systems. Human bone contains about 15% magnesium whitlockite, 25% of the Na and CO3 containing apatite and the rest is the carbonated calcium phosphate with Ca/P = 2. It is presumed that this compound has a structure similar to that of octo calcium phosphate and that most of the citrate ions which always occur in bone mineral samples are in­ corporated in that phase.
Calliphorin, a Protein Involved in the Cuticle Formation of the Blowfly, Calliphora vicina
Authors: Scheller Klaus , Zimmermann Hans-Peter , Sekeris Constantin E. 
Published: August 2018

Abstract
Injections of radioactively labelled calliphorin into Illrd instar larvae of Calliphora indicate that the protein is incorporated into the integument. Immunofluorescence techniques show that the endocuticle is the Final site of deposition of calliphorin. It is concluded that calliphorin is an essen­ tial protein of the tanned cuticle.
Degradation of 3,9-Dimethoxypterocarpan and Medicarpin by Fusarium proliferatum
Authors: Weltring Klaus-Michael , Barz Wolfgang 
Published: August 2018

Abstract
The degradation of 3,9-dimethoxypterocarpan was investigated in selected strains of Fusarium. Fusarium proliferatum (i. e. Gibberella fujikuroi (SAW)WR) degrades this substrate via 3-meth-oxy-9-hydroxypterocarpan, 3,9-dihydroxypterocarpan and 2',4',7-trihydroxyisoflavan. During degradation by this organism medicarpin is first demethylated to 3,9-dihydroxypterocarpan.
The Effect of Phytochrome and Proteinsynthesis-Inhibitors on the Formation of Chlorophylls and Carotenoids in Radish Seedlings Treated with Photosystem II and Bleaching Herbicides
Authors: Grumbach K. H. , Drollinger M. 
Published: August 2018

Abstract
Etioplasts of radish seedlings treated with photosystem II (DCM U, bentazon) and chlorotic herbicides (amitrole, SAN 6706) were tested on their ability to perform the phytochrome mediated chlorophyll and carotenoid biosynthesis. The cytoplasmic influence on the chloroplastic action of herbicides was also investigated by inhibition of protein synthesis either in the chloro­ plast with chloramphenicol or in the cytoplasm with actidion.
In all herbicide treated radish seedlings a phytochrome mediated chlorophyll and carotenoid biosynthesis was obtained as found in control plants. In plants treated with DCM U the bio­ synthesis of carotenoids is enhanced compared to the control plants, while SAN 6706 significantly suppresses the carotenoid formation.
It is concluded, that photosystem II and chlorotic herbicides do not interfere with the primary action of phytochrome but rather do develope their effects on the terpenoid metabolism through phytochrome.
Chloramphenicol applied at the time of sowing very strongly suppresses the formation of chlorophylls and carotenoids in control plants. The sensitivity towards actidion is, however, very much lower. If chloramphenicol and actidion treated plants were also supplied with herbicides, the pigment pattern is completely different In SAN 6706-treated plants chloramphenicol acts synergistic, resulting in an even lower chlorophyll and carotenoid content than in plants supplied only with chloramphenicol. On the other hand SAN 6706 in combination with actidion enhances the formation of pigments, leading to a much higher chlorophyll and carotenoid content as in plants treated only with actidion. A stimulatory effect on the formation of chlorophylls and carotenoids was also found for DCMU-treated plants in combination with actidion.
The observation, that in plants treated with SAN 6706 together with actidion, which inhibits protein synthesis in the cytoplasm, the herbicidal response in the chloroplast is completely abolished, gives evidence that the photooxidative action of SAN 6706 in the chloroplast is developed by the cytoplasm.
Formation of Actin Clusters in Rat Liver Parenchymal Cells on Phalloidin Poisoning as Visualized by a Fluorescent Phallotoxin
Authors: Jahn Wemer , Faulstich Heinz , Deboben Axel , Wieland Theodor 
Published: August 2018

Abstract
By staining of cryo-sections of rat liver with a fluorescent phallotoxin, the distribution of filamentous actin in liver cells could be demonstrated by fluorescence microscopy. While in untreated livers filamentous actin forms an almost continous layer at the cell periphery, the poisoning by phalloidin leads to the formation of actin clusters, preferentially located near the cell membrane.
The Determination of Prolamellar Bodies and Saponins in Etioplasts and Leaves of Avena sativa L.
Authors: Lütz Cornelius 
Published: August 2018

Abstract
Prolamellar body tubules in etioplasts are composed mainly of two saponins. The determination of these saponins in leaves, etioplasts or subfractions of etioplasts is recommended to evaluate the concentration of these tubules in a given fraction. Using a densitometer after TLC-separation of the saponins measurements are carried out in a short time with high accurancy. Also the absolute concentration of these saponins can be determined. Problems in the quantification of the saponins in leaf samples can be overcame with filters of different wavelengths.
On the Reactivity of Pyridoxal-5'-phosphate with Yeast tRNAPhe and tRNATyr
Authors: Okabe Nobuo , Cramer Friedrich 
Published: August 2018

Abstract
Yeast tRNAPhe, Yeast tRNATyr, Pyridoxal-5'-phosphate Yeast tRNAPhe and tRNATyr were reacted with the fluo­ rescent reagent pyridoxal-5'-phosphate and the modified tRNAs were analysed with respect to the number and posi­ tion of modified nucleosides and with respect to amino-acylation.
a) Following the intrinsic fluorescence of pyridoxal-5'-phosphate, the treatment of tRNATyr with increasing amounts of pyridoxal-5'-phosphate revealed about 50 mol of reagent or a even higher number bound per one mol of tRNATyr. After borohydride reduction (in order to stabilize the linkage) of this modified tRNATyr and purification with reverse phase
b) Both tRNATyr and tRNAPhe treated with pyridoxal-5'-phosphate and reduced exhibited almost unchanged aminoacylation as compared to the unmodified tRNAs.
c) Pyridoxal-5'-phosphate treated and reduced tRNAPhe and tRNATyr were digested with ribonuclease T1 and the resulting oligonucleotides were separated. However, no flu­ orescent oligonucleotide and no difference to an oligonucleotide pattern obtained from unmodified tRNA were observed.
Thus, pyridoxal-5'-phosphate might have been bound to the highly purified yeast tRNAPhe and tRNATyr samples either via an unstable linkage or not covalently. This result is controversial with respect to the specific reaction of pyridoxal-5'-phosphate with unfractionated tRNAs from colon carcinoma and tRNAs from E. coli as reported in the literature.
Immunological Studies of Catechol Methyltransferase from the Yeast Candida tropicalis
Authors: Veser Joseph , Thomas Helmut 
Published: August 2018

Abstract
Immunization of rabbits with purified catechol methyltransferase from Candida tropicalis yielded a potent antiserum. Ouchterlony double diffusion analysis showed a single precipitin line. There was no cross reactivity with the catechol methyltransferase from rat and bovine liver. Specific antigen-antibody interaction was demonstrated by a potent inhibitory effect of the antibody on the yeast enzyme. Immunological titration and quantitative precipitin reaction of the enzyme showed that the maximum amount of precipitable complex occurred at the equivalence point where enzyme activity was completely inhibited.
Running Activity Patterns of Females and Last Larval Instars of the Cockroach Leucophaea maderae
Authors: Wiedenmann Gottfried , Martin Wolfgang 
Published: August 2018

Abstract
Virgin females of Leucophaea maderae reveal a circadian rhythm in their locomotor activity which is superimposed by the ovarial cycle. Locomotor activity of last larval instars does not exhibit a circadian pattern.
Ein neues Kämpferolacylglycosid aus Phyllitis scolopendrium / A New Acylated Kaempferol Glycoside from Phyllitis scolopendrium
Authors: Karl Christian , Pedersen Peter Alsted , Müller Gerhard 
Published: August 2018

Abstract
From methanolic extracts of fresh aerial parts of Phyllitis scolopendrium (L.) Newm. a new flavonoid, kaemp­ ferol 3-O-β-{(4-O-caffeyl-3-O-β-glucosyl)-glucoside}-7-O-rhamnoside, was isolated and the structure determined by means of spectroscopic methods including 13C-NMR, and enzymatic hydrolysis.
Enzymatic Synthesis o f Sinapoyl-L-M alate from 1-Sinapoylglucose and L-M alate by a Protein Preparation from Raphanus sativus Cotyledons
Authors: Tkotz Norbert , Strack Dieter 
Published: August 2018

Abstract
Protein preparations from cotyledons of Raphanus sativus transfer the sinapoyl moiety of 1 -sinapoylglucose to L-malate to form sinapoyl-L-malate. To our knowledge this is the first time that this type of reaction has been found to be involved in phenylpropanoid depside formation. Most acylation reactions have so far been demonstrated to depend on acyl-CoAs and only one example is known describing 1-O-acyl sugar derivatives as acyl donors.
The Primary Structure o f the Monomeric Hemoglobin (Erytrocruorin) Component CTT IV o f Chironomus thummi thummi (Insecta, Diptera)
Authors: Pfletschinger J. , Plagens H. , Braunitzer G. 
Published: August 2018

Abstract
The primary structure of the monomeric hemoglobin (Erythrocruorin) CTT IV from larvae of Chironomus thummi thummi (Diptera) is presented. The sequence was determined automatically. The primary structure is com­ pared with human α-globin-chain.
Purification and Properties of a New Enzyme from Evernia prunastri, which Reduces ʟ-Usnic Acid
Authors: Estévez M. P. , Cátedra de Fisiología Vegetal, Facultad de Biología, Univers E. , Olmeda L. , Pérez F. J. 
Published: August 2018

Abstract
new enzyme, usnic acid dehydrogenase, which catalyzes the reduction of ʟ-usnic acid, has been isolated from cell-free extract of Evernia prunastri thallus. Purification of the enzyme (approx. 150-fold with a recovery of 42%) can be achieved by using gel adsorption and gel filtration techniques. The apparent molecular weight of the enzyme is 450000. Cofactor requirement is restricted to NADH. Kinetics of the enzyme show an allosteric behaviour for both ʟ-usnic acid and NADH. Structure of the reaction product is described.
Medium-Induced Formation of Indole Alkaloids and Concomitant Changes of Interrelated Enzyme Activities in Cell Suspension Cultures of Catharanthus roseus
Authors: Knobloch K.-H. , Hansen B. , Berlin J. 
Published: August 2018

Abstract
Recently medium conditions have been developed which stimulate the formation of the indole alkaloid ajmalicine in cell suspension cultures of Catharanthus roseus [6]. When cells were subjected to these conditions the alkaloid accumulation was preceded by a 12-fold increase of the specific activity of tryptophan decarboxylase. The enzyme activity showed a maximum two days after the cell transfer into the induction medium and subsequently declined. In contrast the activity of strictosidine synthase, the enzyme condensing tryptamine and secologanin, was present over the entire measuring period at a constant level. The intracellular content of tryp­tamine and ajmalicine increased during a period of 6 days after cell transfer and reached a plateau after that time. A possible regulatory function of tryptophan decarboxylase in indole alkaloid biosynthesis is discussed.
Pressure, Temperature and pH Dependence of the Absorption Spectrum of Reduced Nicotinamide Adenine Dinucleotide
Authors: Jaenicke Rainer , Liidemann Hans-Dietrich , Schmid Gerhard 
Published: August 2018

Abstract
Enzymological studies at high hydrostatic pressure generally involve temperature, pH and pressure as variables, owing to the effect of adiabatic compression and the ionization volume of the buffer system. In the case of NAD dependent oxidoreductases this implies that the extinction coefficient of the coenzyme may be affected by p, T and pH, apart from the spectral change accompanying the redox reaction.
Measurements of the pressure dependence of the absorbance of NADH show a slight red shift and a 1% decrease (3% increase) of the absorbance at 339 nm (360 nm) at 2 kbar. The pH depen­dence at the given wavelengths amounts to -(2.4 ± 0.1)% per pH unit (25 °C), while the intrinsic temperature effect (after correction for thermal expansion) is of the order of -0.2% per degree (20-30 °C).
Applying buffers with negligible ionization volume, 366 nm is the optimum wavelength for high pressure studies up to 2 kbar because here the pressure dependent spectral changes of the NADH absorption vanish.
Trypsin-Mediated Removal of Herbicide Binding Sites within the Photosystem II Complex
Authors: Steinback Katherine E. , Pfister Klaus , Amtzen Charles J. 
Published: August 2018

Abstract
Trypsin treatment of isolated chloroplast thylakoids resulted in a step-wise modification of surface exposed membrane polypeptides. Early effects of the protease action resulted in a decrease in inhibitory activity of atrazine, diuron, pyrazon, and bromacil, but an initial increase in the activity of bromnitrothymol and dinoseb. Direct measurements of atrazine binding demonstrated that decreased inhibitory activity corresponded to a decreased binding affinity in the treated membranes. Longer term effects of trypsin caused removal of atrazine binding sites and a concomitant block of electron transport chains. The data are consistent with a concept that the traizine receptor protein is a component of the electron transport chain which is successively degraded in two or more steps by protease attack.
Polyacrylamide gel electrophoresis of trypsin-treated membranes and sub-membrane fragments derived from these membranes revealed that several polypeptides are membrane surface exposed. The involvement of a 32000 dalton polypeptide in creating the atrazine binding site is discussed.
Binding of Polylysine and Ethidium Bromide to Nucleosomal DNA: Comparison of Biochemical and Electron Microscopical Results
Authors: Marx Ruth , Doenecke Detlef 
Published: August 2018

Abstract
Ethidium bromide and polylysine interact with nucleosomal DNA and lead to changes of biochemical properties and to morphological changes as to the distance between the two core particles of a nucleosome dimer.
With increasing polylysine concentration, the buoyant density of nucleosomes decreases and the accessibility of the nucleosomal DNA to micrococcal nuclease is lowered. Electron microscopy of polylysine treated nucleosome dimers reveals a shortening of the intemucleosomal distance as compared with controls.
Treatment of nucleosomes with ethidium bromide leads to an enhanced accessibility of the nucleosomal DNA to micrococcal nuclease. Electron microscopy reveals an increase in length of the DNA connecting the two nucleosome cores in the presence of the dye.
Both the binding of polylysine and the treatment with ethidium bromide apparently do not affect the histone arrangement within the nucleosome core as suggested by chemical cross-linking of histones and DNA with formaldehyde, and no obvious morphological changes of the nucleosome cores can be observed.
Cytochalasin B-Induced ATPase Activity of Actin: Dependence on Monomer Concentration
Authors: Dancker Peter , Kliche Agnes 
Published: August 2018

Abstract
We simultaneously measured polymerization and ATPase activity of actin induced by cytochalasin B. It was found that under all conditions tested, ATPase activity was proportional to the concentration of actin which was unpolymerized. In addition, it was found that conditions increasing ATPase activity also increase the velocity of polymerization. From this we conclude that CB-induced ATPase activity is a property of the actin monomers and that the “readiness” of the monomers to hydrolyze ATP is correlated with an increased capacity of the monomers to polymerize.
Investigations on Hoya species. VIII*. Leaf Flavonols and Di-C-glycosylflavones
Authors: Niemann Gerard J. , Dellamonica Georgette , Chopin Jean 
Published: August 2018

Abstract
Nine Hoya species were investigated for their leaf flavonoids. Four species contained flavonols identified as the 3-diglycosides of kaempferol and/or isorhamnetin, in some species acylated with ferulic and/or p-cumaric acid. Five species had no flavonols but were rich in flavones. Identified were: schaftoside, isoschaftoside, di-C-arabino-sylapigenin and vicenin 2.
Steroide menschlicher Thymi / Steroids of Human Thymi
Authors: Reisch Johannes , El-Sharaky Ahmed S. 
Published: August 2018

Abstract
Analysis of human thymus steroids by liquid-gel chro­matography and gas chromatography-mass spectrometry revealed in dependence of age 4-pregnene-3,20-dione, 11β-hydroxy-4-pregnene-3,20-dione, 7β-hydroxycholesterol, and 7-ketocholesterol. 11β-Hydroxy-4-pregnene-3,20-dione should be the inhibitor of immune maturation.
Gaschromatographic, Mass-and Infrared-Spectrometric Identification of Cyclic Adenosine-3': 5'-monophosphate (c-AMP) in Maize Seedlings (Zea mays)
Authors: Janistyn Boris 
Published: August 2018

Gaschromatographic, mass- and infrared-spectrometric evidence is presented for the identification of adenosine-3':5'-monophosphate (c-AMP) in maize seedlings (Zea mays).
The genuine c-AMP content could be quantitated by GC-detection and refere to authentic c- AMP standards
In Vivo Control of Glutamine Synthetase in the Facultative Phototrophic Bacterium Rhodopseudomonas sphaeroides
Authors: Engelhardt Harald , Klemme Jobst-Heinrich 
Published: August 2018

Abstract
In vivo control of glutamine synthetase (GS) in the facultative phototrophic bacterium Rhodopseudomonas sphaeroides was studied. The enzyme was partially purified from cells grown photosynthetically in ammonium-malate-medium. Its catalytic properties were characteristically changed by incubation with phosphodiesterase indicating an in vivo regulation by adenylylation/deadenylylation. Adenylylation states of GS were measured as a function of variations in the nitrogen source and the light intensity during photosynthetic growth.