bluuebunny/crossref_metadata_2025 huggingface dataset:
Perturbation of Growth and Metabolism in Candida albicans by 4-Bromobenzyl Isothiocyanate and Iodoacetate
Authors: Hasilik A.
Published: August 2018

The inhibition by PBBI of growing Candida albicans was studied; additional information was obtained from the analysis of regeneration. The type of the growth inhibition depended on the cell suspension. At more than 107 cells per ml, the inhibition was transient; the inhibitor was taken up rapidly by the cells to a limit of 37 nmoles per mg dry wet. At higher doses, the growth was inhibited permanently, and then, and only then, a lethal effect was observed. At sublethal doses of the inhibitor, the following effects were observed: Inhibition of respiration without apprecciable .change in R.Q., of incorporation of labelled precursors into proteins and nucleic acids, and of eight of fourteen enzymes studied; the level of total free thiol groups was lowered; and a cross- over between hexose monophosphates and fructose diphosphate was induced. The original activities of the enzymes and metabolic processes inhibited were restored coincidentally with the reappearance of growth of the cells. Inhibition of G-6-PDH, PFK and of an early step in the oxidation of NAD(P)H appeared to be determinative for the growth.

In the cells inhibited transiently by iodocetate, GAPDH and ADH were the most sensitive enzymes. The activity of the latter but not of the former was readily restored. The R.Q. was lowered, and was restored later than growth. The cells which recovered from the inhibition by iodoacetate appeared to be physiologically different from the control.
Flavonoide von Larrea tridentata / Flavonoids of Larrea tridentata
Authors: Chirikdjian Jean Jacques
Published: August 2018

The presence of 20 flavonoids has been detected in herbs of Larrea tridentata. Six pigments were isolated and characterized by chromatographic and spectrophotometric methods (shifts with several reagents), acid hydrolytic and alkaline cleavage and finally by comparison with authentic samples.

The structure of this compounds has been established as: quercetin-3-rhamnoglucoside, quercetin-3-glucoside, kaempferol-3-methyl ether, quercetin-31-methyl ether, kaempferol and quercetin.
Tagesrhythmus des Ribosomensystems der Rattenleber unter der Wirkung von Cycloheximid / Daily Rhythm of the Ribosomal System in Rat Liver after Application of Cycloheximide
Authors: Dieminger Lothar
Published: August 2018

Intraperitoneal injections of 2 mg or 5 mg cycloheximide per 100 g body weight into male Sprague-Dawley rats, 3 months old, induce a doubling of the amount of membrane-bound ribosomes after 1 hour. After 2-3 hours the control value is readied and a slow decrease in the number of bound ribosomes can be observed thereafter. The concentration of free ribosomes decreases very markedly during the first hour after injection and more slowly during the following time. Injections of cycloheximide (5 mg / 100 g; 20 min before sacrifice) at different times of day result in a bimodal curve of bound ribosomes with maxima at 9-12 h and 21 h, the maxima of free ribosomes appears at the same time as the maximum of the controls (9-12 h). Analysing the amount of bound ribosomes 3 hours after the injection of cycloheximide a bimodal rhythm can also be observed, the latter curve, however, is phaseshifted for 3-6 hours and appears at a lower level. No rhythm can be detected in the free ribosomal fraction after this treatment. Administration of cycloheximide causes a decrease in protein content of both free and bound ribosomes.
Zur Chemotaxonomie der Rabenvögel. Zusammensetzung der Bürzeldrüsensekrete der Dohle (Coloeus monedula), Raben- (Corvus corone corone) und Nebelkrähe (Corvus corone cornix) / Chemotaxonomy of Corvidae. The Uropygial Gland Fat from the Jackdaw (Coloeus monedula), Carrion Crow (Corvus corone corone) and the Hooded Crow (Corvus corone corvix)
Authors: Jacob Jürgen , Grimmer Gernot
Published: August 2018

The uropygial gland fat from the jackdaw, the carrion and the hooded crow are shown to be ester waxes. Chemotaxonomically the latter two are undiscernible. Their uropygial waxes consist of 4- and 6-monomethyl-, 4.6-, 4.8-, and 4.10-dimethyl- and 4.6.10- and 4.6.12-trimethyl- substituted fatty acids and n- (59.7%) as well as monomethyl-branched alkanols with branches in 4-, 6-, 10-, and 14-position. In contrast to the jackdaw they show no relation to the earlier investigated rook.

The uropygial gland fat from the jackdaw is composed of n- (35.7%) and 2-methyl-substituted fatty acids (64.3%) and w-(87.5%) and 2 methyl-substituted alkanols (12,5).
Abbau und Toxizität von Hexachlorbicyclo [2.2.1]-hept-5-en- Derivaten (Cyclodien-Insektizide) / Structural Aspects of Biological Conversion and Toxicity of Hexachloro-norbornene Derivatives (Cyclodiene-Insecticides)
Authors: Rückert W. , Ballschmiter K.
Published: August 2018

The aspects of molecular-structure and biological conversion have been studied for 12 derivatives of the endosulfan ether 1 [4, 5, 6, 7, 8, 8- hexachloro- 1, 3, 3a, 4, 7, 7a- hexahydro- 4, 7-methanoisobenzofuran]. Adults of a normal house-fly strain (Musca domestica) have been used in the assay.

Derivatives of 1 monosubstituted in position I are found to be converted substantially faster than products disubstituted in position I and 3, respectively. Metabolism is inhibited for all compounds studied after application of piperonyl butoxide as a synergist. Besides proving that on oxidative metabolism has to be discussed and in fact could be proved for some derivatives, the intrinsic toxicity of the compounds studied shows up under these conditions. Some derivatives known to be metabolites of the pesticide Endosulfan® show a high intrinsic toxicity to houseflies if the oxidative metabolism is inhibited.
Light-induced Changes of Radioactivities in the 14C-labeled Lipids and Fatty Acids of Dark Grown Euglena gracilis
Authors: Pohl P.
Published: August 2018

Euglena gracilis was grown in the dark for 12 days in a medium containing sodium acetate- 1-14C. The major amount of 14C was incorporated into the neutral lipids. In these compounds myristic acid was the main fatty acid labeled. Subsequent growth in light (70 hours) in an identical medium (containing unlabeled acetate) led to a strong decrease of radiocarbon in the neutral lipids. The radioactivities in phosphatidyl choline and phosphatidyl ethanolamine increased during the first 28 hours of illumination and thereafter decreased. The radioactivities in phosphatidyl glycerol, sulfolipid, monogalactosyl diglyceride and digalactosyl diglyceride increased continously. After 70 hours of illumination, most of the radiocarbon was detected in the saturated and unsaturated C16 and C18 fatty acids of these four lipids. The possibility of light-induced transfers of fatty acids from neutral lipids via phospholipids to the galactolipids is discussed.
Effect of Irradiation on Amino Acid in vitro Incorporation in the Course of Liver Regeneration
Authors: Tasheva Bistra , Markov George , Tsanev Roumen
Published: August 2018

The in v itro incorporation of 14C-leucine by rat liver microsomes is studied under four different physiological states: 1. Norm al liver of adult rats (N L), 2. irradiated (4 000 rads) liver (IL), 3. liver after partial hepatectomy (RL) and 4. regenerating liver in preirradiated rats (IRL) 2, 5, 12, and 24 hours after treatment.

Both irradiation and partial hepatectomy, when applied separately, stimulate the endogenous activity of microsomes, whereas preirradiation abolishes the stimulatory effect in the early hours after partial hepatectomy.

The results are in agreement with the concept that irradiation stimulates the operating synthetic programme of the cell and inhibits cellular reprogramming.
1. Artificial Receptor for Influenza Virus
Authors: Huang R. T. C. , Rott R. , Klenk H.-D.
Published: August 2018

Neuraminidase-treated erythrocytes coated with a variety of neuraminic acid-containing glycoproteins adsorbed influenza virus and neuraminidase-free hemagglutinins, but not purified neuraminidase. The results indicate that neuraminic acid is the binding site on the glycoprotein and that the rest of the molecule does not play a specific role in the reaction.
Action of Polymyxin B on Bacterial Membranes, I. Binding to the O-Antigenic Lipopolysaccharide of Salmonella typhimurium
Authors: Bader J. , Teuber M.
Published: August 2018

Polymyxin B (PX) forms complexes with the O-antigenic lipopolysaccharide (LPS) of Salmonella typhimurium which are stable in aqueous 0.14 ᴍ sodium chloride at neutral pH. PX can be quantitatively recovered from the complex by changing the pH from 7 to 1, or by treatment with the cationic detergent cetylpyridinium chloride. This proves that complex formation does not involve covalent linkages, but is due to electrostatic, and possibly hydrophobic interactions. Quantitative investigations of the binding properties of mutant LPS of the chemotype Rc and Re, of degraded polysaccharide and isolated lipid A point to the negatively charged ketodeoxyoctonate-lipid A region of LPS as binding site for PX. These biochemical results are confirmed by a blueshift of the fluorescence emission maximum of LPS-bound mono-Ar-dimethylaminonaphthalenesulfonyl PX from 550 to 515 nm which corresponds to a location of the dansyl-PX at a polar-apolar interface34. Using a published molecular weight of the Rc LPS of 10 00029, it is calculated that one LPS molecule can bind 2.7 molecules PX. It is discussed that the PX-LPS interaction may be necessary to alter the permeability of the outer membrane which is a prerequisite for the antibiotic to gain access to it’s final target, the cytoplasmic membrane.
Bürzeldrüsensekrete von Webervögeln (Ploceidae) / The Uropygial Gland Secretion of Weaver-birds
Authors: Poltz Jens , Jacob Jürgen
Published: August 2018

The uropygial gland wax of the genus Ploceus is found to be mainly one wax consisting of 2,4- dimethyl-heptanoic acid and n-octadecanol. The wax of one species of the genus Quelea investigated, mainly has two components consisting of 2,4,6-trimethyl-nonanoic acid and n-octadecanol as well as n-hexadecanol. The wax of the sparrows (Passerinae) belonging to the same family Ploceidae is quite different from the uropygial gland fat of these genera by the occurrence of 3-methyl fatty acids and 3-methyl-alcanols.
Compounds of the Cysteine-cysteamine Group and their Influence on Infectivity, Strand Breaks and Base Damage in Gamma-irradiated DNA of Coliphage ΦX-174
Authors: Stephan Günther , Hotz Gerhart
Published: August 2018

Single- and double-stranded (RF) DNA of page ΦX-174 were 60Co-gamma irradiated. Dependence of radiosensitivity on the concentration of cysteamine and cystamine was measured. Radioresistance of DNA in vivo (phage particles) as well as of DNA in vitro (infectious DNA) increase between 10-4 and 10-1 ᴍ of superprotective agents. The same relationship is observed when the DNA is in the dry and in the wet state. By fractionating radiation damaged RFI and radiation induced RFII by means of sucrose gradient sedimentation it was possible to measure the protective effect of cysteamine on lesions other than strand-breaks. A pronounced radioprotective effect of cysteamine on the production of single-strand breaks in RF -DNA was found (DRF 20). The convenience of the RF system for studying effects of radioprotective agents on the occurrence of different radiation induced lesions is discussed.
Interaction of Bilirubin with Human Serum Albumin and Cationic Detergents
Authors: Lou Jørgen , Birdi K. S.
Published: August 2018

Bilirubin shows a red-shift in the visual spectra on binding to albumin. In bilirubin-cationic detergent systems a similar spectral change was observed. These comparisons allow one to deduce that the environment of the binding site in albumin is most likely apolar than when bilirubin is solubilized by the cationic detergents.
Oscillatory Oxidation of Malonic Acid by Bromate 3. CO2 and BrO3
--Titration
Authors: Bornmann L. , Busse H. , Hess B.
Published: August 2018

The reaction of malonic acid and bromate in the presence of catalytic amounts of cerious ion under oscillating conditions in sulphuric acid was investigated. After two hours reaction time 26 mM bromate were consumed and 42 mM CO2 produced. No formic acid was detected. Furthermore, 14C-tracer experiments suggest that malonic acid is first brominated and subsequently decarboxylated.
Landing Reaction of Musca domestica , III: Dependence on the Luminous Characteristics of the Stimulus
Authors: Taddei-Ferretti Cloe , de Talens Antonio Fernandez Perez
Published: August 2018

1. The house fly shows landing reaction to an expanding visual stimulus or to a decrement of the environmental light level. The quantitative relationship between the dependence of landing reaction on expansion and on light level decrement is analyzed. 2. The different properties of the reactions at different light levels may be correlated with the two visual systems in Diptera and may be explained by the existence of an alterting mechanism that weighs stimuli for landing reaction at low illumination levels. 3. The landing reaction resembles the optomotor reaction with respect to the influence of the contrast of the stimulating pattern. The landing reaction appears to be invariant to the phase relations between the spatial components of the periodic patterns used in the present experiments. Introduction
Measurements on the pH Dependence of Metarhodopsin Reactions in Sonicated Rod Outer Segments
Authors: Stieve Hennig , Wilms Manfred , Noll Gottfried
Published: August 2018

The kinetics of rhodopsin photolysis in sonicated suspensions of rod outer segments (ROS), unsonicated ROS suspensions and rhodopsin detergent solutions were compared. No significant kinetic differences were detected ; however, the energy of activation for the metarhodopsin I to metarhodopsin II reaction was somewhat higher in sonicated ROS suspensions than in the unsonicated suspensions. While the sonicated preparations contained glycerol, it was not possible to show a chemical influence of glycerol on the reactions of the rhodopsin decay. An often assumed effect that the ROS outer membrane acts as a barrier toward diffusion of protons could not be confirmed.
Unimpaired de novo Synthesis of 4-Aminobenzoate in a Mutant of Aerobacter aerogenes Requiring 4-Aminobenzoate for Growth; Structure of Compound A
Authors: Bacher A. , Gilch B. , Rappold H. , Lingens F.
Published: August 2018

The mutant strain Aerobacter aerogenes 62-1 AC, pab-, accumulates a labile substance, desig­nated Compound A which supports the growth of other pab- mutants. Previous studies seemed to indicate that Compound A might be an intermediate in the conversion of chorismate to 4-amino-benzoate (Altendorf, Bacher, and Lingens, Z. Naturforsch. 24 b, 1602 [1969]). The present experi­ ments show that Compound A is 4 -(D-glucosylamino)-benzoic acid. This substance which is clearly not an intermediate in the biosynthesis of 4-aminobenzoate is formed by reaction of 4-aminobenzoate produced de novo by the mutant with exogenous glucose. Mutant 62-1 AC has the unimpaired capacity to synthesize 4-aminobenzoate as shown by direct enzyme studies. Mutant 62-1 AC re­ quires approximately 200 times more 4jaminobenzoate for growth than other pab" mutants of A. aerogenes with defective 4-aminobenzoate synthetase. The genetic defect of mutant 62-1 AC seems to be located in a metabolic system concerned with the utilization of 4-aminobenzoate rather than its synthesis.
Recovery of the Nucleic Acids of Tobacco Mosaic and Potato X Viruses from Polyacrylamide Gel and Evidence for a Single Infectious Component in Each of the Two Viruses
Authors: Sarkar Satyabrata
Published: August 2018

RNA, tobacco mosaic virus, potato X virus, gel-electrophoresis, infectivity A simple device is standardised for the elution of biologically active ribonucleic acid from polyacrylamide gel after electrophoresis. The pieces of gel containing the nucleic acid to be re­ covered are held in position by two short cylinders of foam rubber in a glass tube and the nucleic acid is concentrated over a sucrose-containing buffer layer by electrophoresis in a standard electro­ phoretic equipment. Using this method nucleic acids can be recovered undamaged almost quanti­ tatively, as shown for microgram quantities of two viral RNAs by infectivity assay. The results offer additional experimental support to the single-component character of tobacco mosaic and potato X viruses.
Monoterpene Hydrocarbons from Ants
Authors: Hayashi N. , Komae H. , Hiyama H.
Published: August 2018

Pristomyrmex pungens Mayr, Pheidole nodus Smith, Lasius

(Dendrolasius) spathepus Wheeler, Crematogaster laboriosa Smith, monoterpene hydrocarbons (α-pinene, β-pinene, camphene, limonene)
Stepwise Protonation of PO4
3- , ADP and ATP Salts, IR Investigations
Authors: Hofmann Klaus P. , Zundel Georg
Published: August 2018

IR spectra of aqueous solutions of PO4
3-, ADP3-, ATP4-, MgADP- and (MgADP- + PO4
3-) (in two cases hydrated layers) were plotted. The parameter for the investigation was the mole percent of protons relative to the anions. The other cations were sodium or potassium. The purpose of our work was to obtain a basis for understanding the results regarding the changes to the interactions in ATP systems on hydrolysis. The addition of protons to the different acceptors is discussed on the basis of the bands of the phosphate groups and of the base ring vibrations.

The formation of easily polarizable hydrogen bonds could be demonstrated with the aid of an IR continuum. Such OH+···O bonds between hydrogen phosphate ions as well as NH+,,-N bonds form in the systems investigated. Thus the conditions for forming such bonds and the resulting intermolecular interactions will become evident in this work.
Das allenische Carotinoid Deepoxineoxanthin/ The Allenic Carotenoid Deepoxineoxanthin
Authors: Nitsche Helfried
Published: August 2018

Deepoxineoxanthin, the epoxide-free homologue of neoxanthin, is synthesised in the petals of Mimulus guttatus (Monkey flower). The pigment is esterified with various fatty acids. The free pigment has the structure of 6′,7′-didehydro-5′,6′-hydro-β,β^-carotene-3,3′,5′-triol. These structural conclusions were borne out by the formation of a diacetate (2-sec OH), a mono-silanate of the diacetate (1-tert OH) and a mono-ether of the diacetate and the free pigment (allylic tert OH). PMR, mass and IR spectra supported the proposed structure, which was confirmed by the trans­ formation of deepoxineoxanthin into diatoxanthin with acidified acetone (allene-acetylene trans­formation) and its oxidation to neoxanthin with monoperphthalic acid.
Cluster Orbital Theory Based on Mössbauer Effect Investigations of the (Iron)4-Sulfur Clusters of Clostridium pasteurianum Ferredoxin
Authors: Eicher Hermann , Parak Fritz , Bogner Ludwig , Gersonde Klaus
Published: August 2018

A cluster orbital theory is developed, which allows the calculation of Mössbauer spectra of oxidized and reduced ferredoxin of Clostridium pasteurianum under the conditions of low tempera­ ture (4.2 K) and high external magnetic field (Hex >̃ 1T) . The calculations are based on the symmetry properties of the problem and the way in which these symmetries are reflected in the (iron)4-sulfur cluster wave function. The assumed cubic Td symmetry of the cluster implies an isotropic interaction with the applied external magnetic field, where the average g-tensor is taken to be g -1.944 in accordance with ESR results. The magnetic hyperfine interaction of the cluster electrons with the magnetic dipole moments of the iron nuclei is defined by two parameters ϰ and ϱ reflecting trigonal point symmetry C3V of each iron site. These parameters are determined by a least squares fit of the experimental Mössbauer spectrum of reduced ferredoxin at 4.2 K and H ext = 2 T. In correspondence with the theory, ϰ and ϱ have been proved to be independent of H ext. Despite neglecting small deviations from Td and C3V point symmetry of the center of the cluster and the iron sites, respectively, theory and experiments are in reasonable good agreement.
Ripples in Tilted Bilayers and Lyotropic Smectics
Authors: Helfrich W
Published: August 2018

The elastic theory of tilted lyotropic smectics and single tilted bilayers is extended to include internal twist of the bilayers. The coupling of internal twist to layer curvature offer an explanation for the corrugation or ripples displayed by these structures.
Evidence of the Juvenile Hormone Methyl(2E,6E)-10,11-epoxy- 3,7,11-trimethyl-2,6-dodecadienoate(JH-3) in Insects of Four Orders
Authors: Trautmann K. H. , Masner P. , Schuler A. , Suchý M. , Wipf H.-K.
Published: August 2018

With the help of radioactive dilution analysis allowing the qualitative and quantitative deter­mination of all three presently known juvenile hormones (JH-1 to 3) the following seven species of four orders were investigated in the adult stage: Coleoptera: Tenebrio molitor, Leptinotarsa decemlineata; Orthoptera: Schistocerca gregaria; Blattodea: Blatta orientalis, Leucophaea maderae, Nauphoeta cinerea; Hymenoptera: Apis mellifera.

In all these species of the 3 known juvenile hormones only m ethyl (2E ,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (JH-3) was found, in an amount of 0.5 to 11 ng per gram of body weight. The results of the chemical analyses were confirmed biologically by the Galleria wax test.

The results demonstrate the wide spread occurrence of JH-3 in insects of different orders.
Conformation of Proflavine-Bound DNA Molecules
Authors: Dasgupta Santanu , Misra D. N.
Published: August 2018

Proflavine, DNA, Electron Microscopic Study The conformational changes suffered by full-length double-stranded DNA molecules from bac­ teriophage T7, due to their binding with the mutagenic dye proflavine (PF), has been studied by electron microscopy. The dye-bound DNA showed a smoother contour and a more compact con­ figuration in comparison with the dye-free native DNA. These changes resulted from the stretching, extension and charge-neutralization accompanying the incorporation of PF.
Stimulierung von Kulturen embryonaler Rattenzellen durch Kälberserum, VIII
Authors: Frank W , Ristow H.-J , Veser J
Published: August 2018

Embryonic rat fibroblasts which have been stopped in G1 by incubation in serum-free medium can be triggered to proceed through their cell cycle by the serum proteins S1 and S2. To determine the specificity of these serum factors, a wide variety of compounds have been tested: Proteolytic and lipolytic enzymes, hormones, serum proteins, prostaglandins etc. Slight effects could be de­tected with α2-Macroglobulin-Schultze and Prostaglandin F2α in combination with insulin. Stimulation of the cells comparable to that obtained with S1 can be achieved by treating the cells for 10 min with low concentrations of trypsin followed by incubation in serum-free medium containing insulin. The effect of trypsin can be completely abolished by soybean trypsin inhibitor.
Structure-Activity-Relationship of Inhibitors of Photosynthetic Electron Flow. Herbicidal N-Alkylated-Ureas and Ringclosed N-Acylamides as Inhibitors of Photosystem II
Authors: Trebst A. , Harth E.
Published: August 2018

The inhibitory action of some herbicides on photosynthetic electron flow at photosystem II in isolated chloroplasts was investigated. Emphasis in the study is on compounds, whose chemical structure seemed to be in disaccordance with the basic structural element, proposed to be required for a photosystem II inhibitor. The effective inhibition of photosynthetic oxygen evolution by N-alkylated urea-, pyrrolidone-and by substituted pyridazine-derivatives without a free NH-group is reported. A revised basic chemical structural element responsible for inhibition is deduced in order to include lactames (ringclosed N-acylamides) with and without hetero atoms. From this new groups of potential inhibitors, like triazolone-, thiadiazolone-and oxadiazolone-derivatives may be conceived.
UV-Empfindlichkeit von λ-Phagen mit variablem Bromuracil-Gehalt / UV-Sensitivity of λ-Phages with Various BU-Contents
Authors: Mönkehaus Friedrich
Published: August 2018

Heat induction of E. coli CR 34 (λcI857)/λ growing in media with variing bromouracil (BU)-contents yielded A-phages with different amounts of BU in their DNA-strands. The percentage substitution of thymine was determined by buoyant density measurements in a CsCl-density gradient. After irradiation of the phages with long wavelength UV (302/313 nm) and short wavelength UV (254 nm) the sensitivity (loss of infectivity) was determined as a function of the degree of BU-substitution. It was found that after irradiation with long wavelength UV the cross section is proportional to the percentage BU-substitution, whereas after irradiation with short wavelength UV it is not. The results can be explained by assuming energy transfer from the four DNA-bases to the BU.
Polarographie Reduction of Adenine and Cytosine Residues in Denatured DNA
Authors: Brabec V , Paleček E
Published: August 2018

Polarographie reduction of adenine and cytosine moieties in denatured DNA was followed by means of differential (derivative) pulse polarography. The measurements of the reduction currents yielded by samples of denatured DNA differing in guanine+cytosine (G + C) content showed that both cytosine and adenine residues were reduced in DNA in the pH range of 6.0 -8.7. The contribution of their reduction to the total reduction current of denatured DNA differs in the range pH 6.0 -8.7, however; the contribution of the current of adenine residues to the current of DNA decreases with increasing pH as compared with the contribution of cytosine residues. It was also shown that in the region of neutral pH reduction current of denatured DNA is independent of the G + C content in DNA.
Concerning a Model of Carcinogenesis
Authors: Memory J.D.
Published: August 2018

Several questions are raised concerning the Popp model of carcinogenesis by polycyclic hydrocarbons.
Halogen-Substitution Effect on the Optical Absorption Bands of Uracil*
Authors: Lohmann Wolfgang
Published: August 2018

The ultraviolet absorption spectra of uracil and its 5-halogenated derivatives have been in ­ vestigated in regard to the electron attracting properties of the substituents. It could be shown that the position of the two absorption bands is proportional to the inverse of the electronegativity; the extinction coefficients are a linear function of the electron affinities. In this way, the red shift obtained upon substitution with halogens can be explained. Also, the decrease in absorbance of the absorption bands at λ > 250 nm, occuring concomitant­ ly, is understandable. The increase in absorbance with increasing electron affinity, as observed in the case of the absorption bands at λ < 250 nm, might question the assumption that this band is due to a higher pi -pi* excitation
Blocked Lipid Exchange in Bilayers and its Possible Influence on the Shape of Vesicles
Authors: Helfrich W
Published: August 2018

The role of lipid exchange in the curvature elasticity of bilayers is studied theoretically. Blocking of exchange between the monolayers may give rise to a nonequilibrium lipid distribution going hand in hand with a spontaneous curvature. Some possible consequences for vesicular deformations are discussed. Lipid nonequilibrium is tentatively suggest as one possible cause for certain shape transformations of red blood cells
Structure of Chromatin DNA not Complexed with Protein
Authors: Richter K. Hartmut , Sekeris Constantin E.
Published: August 2018

Rat liver chromatin was titrated by poly-ᴅ-lysine of mol.wt. 140,000. Approximately 32% of the phosphate groups of the chromatin were found to react with the polycation. By submitting the chromatin-poly-ᴅ-lysine complex to pronase and DNase I digestion and by further submitting the obtained DNA-lysine complex to hydroxy-apatite-chromatography, "free" DNA was isolated. The mean S-value of this DNA was found to be 10 ± 0 .8 , corresponding to approximately 2100 nucleo­ tide pairs, its renaturation kinetics similar to total DNA. On the basis of these results and on the findings that histone-saturated DNA-histone recombinates are digested with DNase I up to 65% a model of chromatin structure was proposed, taking into account protein covered-and free DNA regions
Komplexe von Desoxyribonucleinsäure mit Azoverbindungen und Diazinen, I DNA und 2-Amio-benzo[c]cinnolin / Azo Compound and Diazine Complexes of Desoxyribonucleic Acid, I DNA and 2-Amino-benzo[c]cinnoline
Authors: Rau Hermann , Schuster Gisela
Published: August 2018

Complex formation of deoxyribonucleic acid and 2-amino-benzo [c] cinnoline is demonstrated by spectroscopic means. The small molecule though uncharged seems to intercalate between the base pairs of the deoxyribonucleic acid like the acridines. The complex constant, however, is smaller by about two orders of magnitude. The influence of salt concentration and temperature on the equilibrium is investigated. The involvement of charge-transfer contribution is suggested.
Determination of Superoxide Free Radical Ion and Hydrogen Peroxide as Products of Photosynthetic Oxygen Reduction
Authors: Elstner Erich , Stoffer Claus , Heupel Adelheid
Published: August 2018

Formation of Nitrite from Hydroxylamine in the presence of illuminated chloroplast lamellae is inhibited by superoxide dismutase but not by catalase, indicating that the superoxide free radical ion and not H2O2 is responsible for the oxidation of hydroxylamine. Decarboxylation of α-keto acids on the other hand is strongly inhibited by catalase but only slightly by superoxide dismutase. Light-dependent hydroxylamine oxidation and decarboxylation of α-keto acids can be used, therefor, as specific and sensitive probes for the determination of either the superoxide free radical ion or hydrogen peroxide, respectively.

Photosynthetic oxygen reduction in the presence of ferredoxin, (monitored by the above method) yields both H2O2 and O2
·-. The addition of an oxygen reducing factor (ORF, solubilized by heat - treatment of washed chloroplast lamellae) instead of ferredoxin, however, stimulates only the production of H2O2 , while O2
·-
- formation is not observed. The cooperation of ferredoxin and ORF during photosynthetic oxygen reduction by chloroplast lamellae apparently produces H2O2 not only by dismutation of O2
·-, but also by a separate mechanism involving ORF.
Ethylene Formation by Isolated Chloroplast Lamellae in the Dark
Authors: Elstner Erich , Konze Jörg
Published: August 2018

Ethylene Biosynthesis, Chloroplasts, Superoxide Free Radical Isolated chloroplast lamellae from spinach produce ethylene in the dark from methylmercapto-propanal (MMP) or from 2-keto-4-methyl-mercaptobutyrate (KMB) only in the presence of both NADPH and ferredoxin. Anthraquinone-2-sulfonic acid can substitute for ferredoxin. Catalase, superoxide dismutase, ethanol and ascorbate are inhibitors of NADPH-dependent ethylene forma­ tion. Isolated NADP-ferredoxin reductase in the presence of NADPH, ferredoxin and an oxygen reducing factor (ORF, isolated by heat-treatment of chloroplast lamellae) catalyzes ethylene formation from the above substrates in the dark without chloroplast lamellae. From the results it is concluded that chloroplast lamellae in the dark can reduce oxygen monovalently at the expense of NADPH, with the production of the OH-radical as the reactive species responsible for ethylene formation from MMP of KMB.
Irrtümer beim Maschineschreiben und ihr Hinweis auf Systemeigenschaften zentraler Entscheidungsmechanismen / Errors in Type-writing and Their Indications for Special Characters of the Data Processing Controlling the Typing Process
Authors: Todt Dietmar
Published: August 2018

Twenty students having a comparable typing skill and speed (about 150 strokes per min) performed series of typewritings with contents well familiar to them. These writings were examined for errors (error = deviation from a given program of stroke sequences).

The errors could not be caused by ingnorance of writing or spelling of the words. Two categories of errors (“exchanges” = “Verwechslungen” and “omissions” = “Auslassungen”) were explained to result from special “faults” in the data processing controlling the typing process (Fig. 3). The occurrence of these types of errors dependend on interactions of the following factors:

1. Preferences of succession which (in general) related the first letter of an actual letter-combination with the second one (also) in contrary succession (i ⇄ e) or with other letters, not occurring in the combination (n → d ; n → g) (Tab. I ) .

2. Tendencies of the particular letters of an actual sequence of letters ( = word) to occur already before and/or after the right sequential position (sequential interval of this effect ≤ 4 strokes; temporat interval: about 1 sec; Figs 1, 2).

3. Correspondences in particular characteristics of special letters (vowel-vowel-exchange, etc.).

4. The notice to type as quickly as possible. Interactions of these factors resulted in erroneous “anticipations” and “postpositions” of letters.
Problems of Menotactic Orientation According to the Polarized Light of the Sky
Authors: Kirschfeld Kuno , Lindauer M. , Martin H.
Published: August 2018

It is shown that the knowledge of the E-vector direction of the linearly polarized light at any point of the sky alone is insufficient for the determination of the position of the sun. If the E-vector direction of a second point is not known the knowledge of at least one other parameter is necessary. This parameter might be the height of the sun over the horizon. With the knowledge of the height the infinite number of solutions for the sun’s position becomes reduced to two, or in special cases to one. These cases are derived.
Gesetzmäßigkeiten der Substratversorgung, der Zellkinetik und der Therapiemechanismen im Interkapillarraum der Krebsgewebe / Laws of Substrate Supply, of Cell Kinetics and of Therapy Mechanisms in the Intercapillary Region of Cancer Tissue
Authors: von Ardenne M. , von Ardenne A.
Published: August 2018

Up to now, the microtopography of glucose and O2 concentration in the intercapillary region of tumour tissue has been determined under the simplifying assumption that substrate consumption is constant up to the periphery of the envisaged cylindrical space around a capillary. The general diffusion field equation presented in this paper takes into account that substrate consumption decreases in the unsaturated region of cancer cell glycolysis and respiration so that - compared to former computations - the critical supply radii needed for maintained proliferation increase by a factor of almost 1.8. With the aid of its general solution and the discussed parameters, the laws governing substrate supply, cell kinetics and therapy mechanisms in the intercapillary region of intact and treated tumour tissue are presented and discussed. The essential results there are as follows: - Even in case of hyperglycemia it is glucose supply (and not the O2 supply) which determines proliferation and proliferation rate. - Under the conditions of longtime-hyperglycemia (400 mg%), the tumour volume being accessible to the attack of cancerostatica or radiation, is almost three times as high as under standard conditions. - For glucose (and cancerostatica) the time constant for interactions between circulation and tumour tissue near the necrotic region is equal to or greater than 400 min. This is why stimulation of cancer cell glycolysis in the most therapy-resistant cancer cell portions (i. e., increased proliferation rate and tumour hyperacidifica­ tion) can only be achieved if hyperglycemia is maintained for 24 hours or more. - Therapeuti­ cally treated cancer tissue is characterized by the discussed changes in the diffusion field of glucose and O2 as well as a drop in the interaction time constant for glucose.
Influence of Spermine on Some Membrane-disturbing Actions
Authors: Eiferink J. G. R.
Published: August 2018

The influence of spermine on the potassium loss from yeast cells as a consequence of membrane-disturbing actions was investigated. Spermine interfered strongly in the action of membrane-active bactericides on yeast cells; this interference resembles the action of certain metal ions. Spermine provides a protection against the positively charged pararosaniline and accomplishes a strong potentiation of the action of the negatively charged sodium dodecyl sulphate.
Juvenilhormonbindende Substanzen mit allosterischen Eigenschaften in den Ovarien von Tenebrio molitor L. / Juvenile Hormone Binding Substances with Allosteric Properties in the Ovaries of Tenebrio molitor L
Authors: Schmialek Peter , Geyer Astrid , Miosga Verena , Nündel Michael , Zapf Burger
Published: August 2018

Some receptor proteins were isolated from the ovaries of Tenebrio molitor L. One had a molecular weight of 8 × 105 and an isoelectric point of 5.4. In the range of 1 ×

106 - 4 × 107 dalton JH-binding particles are existing with the same isoelectric point of 2.5. All proteins showed allosteric effects. Under the used conditions they are stable against heating and some enzymes, precipitable with 5% trichloro acetic acid and hydrolyzable with 1 ɴ HCl. The binding is specific and not displaceable with a great excess of substances with the same polarity.
Synthese einer Partialsequenz aus dem aktiven Zentrum der Streptokokken-Proteinase (EC 3.4.22.10), VIII / Synthesis of a Fragment of the Active Center of the Streptococcal Proteinase (EC 3.4.22.10), VIII
Authors: Raschig Andreas , Schaich Eugen , Schneider Friedhelm
Published: August 2018

The synthesis of the protected tricosapeptide Z-Val-Lys (Z)-Pro-Gly-Glu (OBzl)-Gln-Ser-Phe-Val- Gly-Gln-Ala-Ala-Thr-Gly-His-Cys(MBzl)-Val-Ala-Thr-Ala-Thr-Ala-ONB is described. The tricosapeptide was built up from the decapeptide Z-Val-Lys (Z)-Pro-Gly-Glu (OBzl)-Gln-Ser-Phe-Val-Gly- ONp and the tridecapeptideester Gin-Ala-Ala-Thr-Gly-His-Cys (MBzl)-Val-Ala-Thr-Ala-Thr-Ala-ONB. A further nonadecapeptide with tert-butylmercapto protection of the SH group was also synthetized.
The Regulation of Glucose-6-phosphate Dehydrogenase in Chloroplasts
Authors: Wildner Günter
Published: August 2018

Glucose-6-phosphate Dehydrogenase, Reduction Charge, Pentosephosphate Cycle, Chloroplasts Glucose-6-phosphate dehydrogenase from intact pea chloroplasts is partially membrane bound and inactivated upon illumination. The inhibitory effect of light can be abolished by addition of methylviologen. Kinetic experiments with glucose-6-phosphate dehydrogenase reveal that, in the dark, the enzyme activity is strongly inhibited by the accumulation of NADPH. The inhibition of NADPH can be reversed by the addition of excess NADP+ . The non-Michaelis-Menten-type kinetics suggest that the enzyme is stringently regulated by the ratio of NADPH to NADP+ plus NADPH, i. e., the “reduction charge”. These observations seem to indicate that in the light the inhibition of glucose-6-phosphate dehydrogenase is due to a high reduction charge, whereas in the dark the enzyme is controlled by the metabolic demand for reducing equivalents.
Antagonistic Relationships between Electron Transport and P700 in Chloroplasts and Intact Algae
Authors: Rurainski Hans
Published: August 2018

The effects of divalent salts and 3-(3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) upon nicotinamide adenine dinucleotide phosphate (NADP) reduction and P700 in isolated chloroplasts are described and compared with the influence of DCMU on oxygen evolution and P700 in intact cells.

Most experiments were carried out with a steady-state relaxation spectrometer. A kinetic mechanism for the estimation of P700 fluxes is proposed and experimentally tested. Good agreement between theory and experiment was found.

Concurrent measurements of P700 and NADP reduction revealed two antagonisms: addition of divalent cations caused an increase in the yield of NADP reduction and a decrease in the yield of P700. Conversely, in the presence of Mg2+ low concentrations of DCMU decreased the yield of NADP reduction and increased the yield of P700 . Aging of the chloroplasts at 30 °C exerted a similar effect.

With far-red actinic light, Mg2+ stimulated the yield of NADP reduction without affecting the flux. Also, in the absence of Mg2+ , DCMU inhibited both reactions although P700 required a higher herbicide concentration for fractional inhibition than NADP reduction.

In the presence of Mg2+, chloroplasts resembled intact algae in which a high rate of oxygen evolution was accompanied by little P700 turn-over. Titration with DCMU decreased the rate of photosynthesis and increased P700 flux.

On the whole, the data suggest that P700 relaxing in 20 msec is not directly involved in linear electron transport.
Inducibility of Lambda Phage Development in Escherichia coli Mutants Thermosensitive for DNA Replication
Authors: Taketo Kira
Published: August 2018

In a thermosensitive dnaZ mutant lysogenic for λ, induction of the prophage development was provoked at the restrictive temperature. In dnaD strain, spontaneous release of λ proceeded even at 43 °C, but distinct induction of the prophage development was not caused by a heat treatment. Similarly, shift up of growth temperature did not lead to induction of λ in lysogens carrying thermosensitive mutation in dnaH function or DNA polymerase I. In dnaH mutant, multiplication of λ-virulent phage proceeded normally at 43 °C.
Some Aliphatic Methyl Esters from Aralia elata Seemann (Araliaceae)
Authors: Watanabe S. , Hayashi Y. , Murayama Y.
Published: August 2018

The dried bark of Aralia elata Seemann was extracted with n-hexane. Methyl pentadecanoate, methyl hexadecanoate, methyl octadecanoate, methyl eicosanoate, methyl docosanoate, methyl tetracosanoate, methyl hexacosanoate, and 1-hexacosene were identified from the extract by means of GC-Mass spectrometer.
Radiation Chemistry of DNA, II. Strand Breaks and Sugar Release by γ-Irradiation of DNA in Aqueous Solution. The Effect of Oxygen
Authors: Dizdaroglu Miral , Schulte-Frohlinde Dietrich , Sonntag Clemens von
Published: August 2018

From γ-irradiated oxygenated aqueous solutions of DNA, 2-deoxy-tetrodialdose (1) and 2-deoxy-pentos-4-ulose (2) have been isolated as free sugars. The formation of 1 indicates that in the presence of oxygen the DNA strand is not only broken by mere phosphate ester cleavage but also by C -C-bond rupture in the sugar moiety. Such a process has not been encountered in deoxygenated solutions so far. The mechanism for the formation of 1 is discussed.
Identification of Functional Groups of Pig Kidney Alkaline Phosphatase by Specific Inhibitors
Authors: Ahlers Jan
Published: August 2018

Inactivation studies with 17 group-specific inhibitors showed that amino, hystidyl and tyrosyl residues probably are components of the active and/or regulatory sites of pig kidney alkaline phosphatase.
Untersuchungen über die Bildung des ätherischen Öls von Matricaria chamomilla L. / Biosynthesis of the Essential Oil by Matricaria chamomilla
Authors: Hölzl J. , Franz C. , Fritz D. , Vömel A.
Published: August 2018

By injecting [1 - 14C] acetate into the flowers of Matricaria chamomilla L. up to two percent were incorporated in the essential oil. The highest labelling was analysed in the en-in-dicycloether, a hydrocarbon and in an unknown polar compound after 12 days incorporation time. The hydrocarbon and the polar compound may be precursors for the other compounds in the essential oil.
The Use of Fluorescent Probes for Studying the Interaction of Proteins with Black Lipid Membranes
Authors: Pohl W. G. , Teissié J.
Published: August 2018

The number of l-anilino-8-naphthalene sulphonate (ANS) molecules bound to black phospha­ tidylcholine (PC) and phosphatidylinositol (PI)-membranes was calculated. The fluorescence change of membrane-bound ANS was measured after the addition of positively charged proteins to the same side as ANS. Cytodirome c caused a fluorescence decrease, lysozyme and protam ine an increase. These effects were completely reversible in the case of cytodirome c and lysozyme and only partly reversible in the case of protam ine by increasing the ionic strength. The fluorescence polarization of membrane bound ANS was not significantly changed by protein addition. The results are dis­ cussed with respect to the binding of proteins to probe compared with other fluorescent probes.
Studies on the Nature of the Primary Reactions of Photosystem II in Photosynthesis
Authors: Wolff Ch. , Büchel K. , Renger G.
Published: August 2018

The effect of a-bromo-α-benzylmalodinitril (BBMD) on the oxygen evolution and on the absorption changes at 515 nm and 704 nm has been investigated in spinach chloroplasts. It has been found: 1. Under repetitive flash excitation conditions, where the back reaction around system II is practically excluded for kinetical reasons, BBMD does not restore the 515 nm absorption change in DCMU poisoned chloroplasts.

2. Under single flash excitation conditions, where the back reaction around system II becomes prominent in the presence of DCMU, BBMD moderately inhibits this back reaction. The deleterious effect is pronounced by preillumination with short flashes during the BBMD incubation period of the chloroplasts in the absence of DCMU.

3. Incubation of the chloroplasts with BBMD leads to an activity loss of oxygen evolution which increases with the time td between the repetitive short excitation flashes and with the dark incubation time. Preillumination during the incubation period with BBMD significantly enhances the effect.

4. In the absence of artificial electron acceptors BBMD suppresses in DCMU poisoned chloroplasts the 704 nm absorption change reflecting an internal cyclic electron flow around system I. On the other hand the linear electron transport at system I mediated by DCIP plus ascorbate as electron donor couple and benzylviologen as electron acceptor is not disturbed by BBMD.

5. BBMD incubation of chloroplasts accelerates the decay rate of the field indicating 515 nm absorption change.

Based on these experimental findings the conclusion has been drawn, that - in contrast to the assumption of Brandon and Elgersma (Biochim. Biophys. Acta 292, 753 - 762 [1973]) - BBMD does not accept electrons from the primary electron acceptor X 320 of system II in DCMU poisoned chloroplasts. BBMD rather acts as a system I electron acceptor.

Furthermore, BBMD exerts deleterious effects on the center of photosystem II, accompanied by a weak ADRY-effect on the water-splitting enzyme system Y. As a tentative explanation of the BBMD-action on system II it is assumed that BBMD transforms the photochemical centers of system II into dissipative energy sinks
NMR Relaxation Study of the Thermal Denaturation of Lysozyme
Authors: Pumpernik D. , Fajt B. , Lapanje S. , Ažman A.
Published: August 2018

Lysozyme relaxation times T1 and T2 have been measured. Methyl groups T1 are sensitive to thermal denaturation of the lysozyme. The exchange of the water molecules between bounded and free is slow
Receptor and Interneuron Light-adaptation in the Dragonfly Visual System
Authors: Laughlin Simon B.
Published: August 2018

Intracellular recordings show that the receptors and second-order interneurons of the dragonfly compound eye change their sensitivity in response to maintained illumination. Comparison of receptor with interneuron shows that neural mechanisms act to ensure that the modulation of interneuron membrane potential that is set up by contrast changes is independent of background intensity.
Schutz von Mäusen gegen Friend-Leukäm ie durch aktive bzw. passive Im m unisierung mit isoliertem Virus-Glykoprotein bzw. seinem Antiserum / Protection of Mice against Friend Leukemia by Active and Passive Immunization with Isolated Viral Glycoprotein and its Antiserum Respectively
Authors: Hunsmann Gerhard , Moennig Volker , Seifert Eveline , Schäfer Werner
Published: August 2018

Mice could be protected against Friend leukemia virus infection by inoculation with highly purified viral glycoprotein GP71 or its specific antiserum