| | 21 | Author
| Regina Teschner, Stefan Postius, M. Onika Löffler, Friedhelm Schneider | Requires cookie* | | | Title
| Cell Proliferation and Metabolism of Ehrlich Ascites Tumor Cells Grown in Chemically Defined Albumin Medium for Several Passages  | | | | Abstract
| Cell proliferation, cell cycle distribution, viability, uptake o f ar-aminoisobutytic acid, cyclo leucine and 2-deoxyglucose as well as DNA, RNA and protein synthesis of Ehrlich ascites tumor cells grown in suspension culture over three passages in serum free nutrient medium supplemented with 1 -2 % bovine serum albumin (Cohn fraction V, Serva) were measured and compared to cells grown in medium supplemented with 15% horse serum. At the end of the fourth passage in vitro, that is the third passage in serum free albumin medium, the growth o f the cells is reduced to about 1 0 % of the controls, accumulation of the cells in G 2 is delayed and the number o f dead cells rises to 30%. The transport rates o f a-aminoisobutyric acid and o f 2-deoxyglucose slowly decrease while the up take of cycloleucine shows a more complex behaviour in albumin medium. Incorporation o f thy midine and leucine into the cells corresponds to the growth rate, while the incorporation o f uridi ne in normal as well as in albumin medium exhibits different pattern. The present experiments demonstrate, that it may be possible to preserve this cells in a fairly "physiological" state during two passages in albumin medium. | | | |
Reference
| Z. Naturforsch. 35c, 117 (1980); received October 29 1979 | | | |
Published
| 1980 | | | |
Keywords
| Albumin Medium, Cell Growth, Ehrlich Ascites Tumor Cells, Metabolism | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0117.pdf | | | | Identifier
| ZNC-1980-35c-0117 | | | | Volume
| 35 | |
| 22 | Author
| Regina Teschner, M. Onika Löffler, Friedhelm Schneider | Requires cookie* | | | Title
| Lipid Metabolism of Ehrlich Ascites Tumor Cells Grown in Chemically Defined Albumin Medium | | | | Abstract
| Total lipids o f Ehrlich ascites tumor cells grown in nutrient medium supplemented with 1% bovine serum albumin instead o f 15% native horse serum and rate o f incorporation of [3H] acetate into total lipids are reduced, while the cholesterol content of the cells is higher than of controls grown in normal medium. The lower lipid content o f cells cultured in albumin supplemented medium is explained by a lack o f exogenous lipids, which are normally taken up from the serum containing nutrient medium. A several fold increase of incorporation o f labelled choline and ethanolamine into the phospholipids o f the cells grown in the modified medium is observed. We suggest, that the observed stimulation of the incorporation o f phospholipid precursors reflects changes in the dynamic state o f the membranes produced by serum depletion. | | | |
Reference
| Z. Naturforsch. 35c, 124—128 (1980); received November 5 1979 | | | |
Published
| 1980 | | | |
Keywords
| Cultured Cells, Albumin Containing Medium, Lipid Metabolism | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0124.pdf | | | | Identifier
| ZNC-1980-35c-0124 | | | | Volume
| 35 | |
| 23 | Author
| ErichF. Elstner, W. Osswald | Requires cookie* | | | Title
| Chlorophyll Photobleaching and Ethane Production in Dichlorophenyldimethylurea-(DCMU) or Paraquat-Treated Euglena gracilis Cells | | | | Abstract
| Light dependent (35 Klux) chlorophyll bleaching in autotrophically grown Euglena gracilis cells at slightly acidic pH (6.5 —5.4) is stimulated by the photosystem II blockers DCMU and DBMIB (both 10~5 m) as well as by the autooxidizable photosystem I electron acceptor, paraquat (1 0 -3 m). Chlorophyll photobleaching is accompanied by the formation o f thiobarbituric acid — sensitive material ("malondialdehyde") and ethane. Both chlorophyll photobleaching and light dependent ethane formation are partially prevented by higher concentrations (10~* m) o f the autooxidizable photosystem II electron acceptor DBMIB or by sodium bicarbonate (25 m M). In vitro studies with cell free extracts (homogenates) from E. gracilis suggest that a-linolenic acid oxidation by excited (reaction center II) chlorophyll represents the driving force for both ethane formation and chlorophyll bleaching. Ethane formation thus appears to be a sensitive and non-destructive "in vivo'' marker for both restricted energy dissipation in photosystem II and, conditions yielding reactive oxygen species at the reducing side o f photosystem I. | | | |
Reference
| Z. Naturforsch. 35c, 129—135 (1980); received August 20/September 28 1979 | | | |
Published
| 1980 | | | |
Keywords
| Chlorophyll Bleaching, Herbicides, Euglena gracilis, Ethane, Fat Oxidation | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0129.pdf | | | | Identifier
| ZNC-1980-35c-0129 | | | | Volume
| 35 | |
| 24 | Author
| H. Daniell, G. Kulandaivelu, U.Chandra Singh | Requires cookie* | | | Title
| Substituted p-Benzoquinones Having High Electron Affinity as Photosystem II Electron Acceptors | | | | Abstract
| Substituted Benzoquinones, Photosystem II Acceptors Benzoquinones (BQ) substituted with alkyl or alkoxy groups 2,5-dimethoxy-3,6-dichloro-/>-benzoquinone (DCDMQ), 2,3,5,6-tetramethoxy-/?-benzoquinone (TMQ) have been tested for their electron affinity and site o f action in the photosynthetic electron transport chain in whole cells and chloroplasts. Both the substituted compounds were found to be good electron acceptors of photosystem II. DCDMQ showed higher electron affinity than BQ as demonstrated by its two fold stimulation of 0 2 evolution in chloroplasts and efficiency in quenching DCMU fluorescence. TMQ on the other hand showed low electron affinity. | | | |
Reference
| Z. Naturforsch. 35c, 136—138 (1980); received May 8 /August 27 1979 | | | |
Published
| 1980 | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0136.pdf | | | | Identifier
| ZNC-1980-35c-0136 | | | | Volume
| 35 | |
| 25 | Author
| Marc Symons, Anthony Crofts | Requires cookie* | | | Title
| Flash-Induced Electrochromic Band Shifts, is It a Simple Mechanism? | | | | Abstract
| The flash-induced carotenoid bandshifts have been studied for various strains of both Rho-dopseudomonas sphaeroides and capsulata. A technique for calculating shifts o f isobestic points down to 0.05 nm is described. To this end, special attention has been paid to the appropriate cor rection for reaction center absorbance changes occuring concommitantly with the carotenoid bandshifts. Plots of the wavelength o f the isobestic point versus the corresponding absorption changes at the maximum o f the difference spectrum have been made, suggesting the existence o f different pools of carotenoids. The various pools of carotenoids seem to have different sizes, in ducing non-linearities in the plots. In some cases spectral differences of the pools have to be assumed. A possible interpretation o f the results would be that each electrogenic span of the electron transport chain is to be associated with its own pool of carotenoids, all the pools behaving in somewhat independant way. We discuss possible difficulties in making those measurements. | | | |
Reference
| Z. Naturforsch. 35c, 139—144 (1980); received August 16 1979 | | | |
Published
| 1980 | | | |
Keywords
| Electrochromism, Carotenoids, Electron Transport, Membrane Potential, Photosynthesis | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0139.pdf | | | | Identifier
| ZNC-1980-35c-0139 | | | | Volume
| 35 | |
| 27 | Author
| Ulrich Fischer | Requires cookie* | | | Title
| A H igh P otential Iron Sulfur Protein o f the Purple Sulfur Bacterium T hiocapsa roseop ersicin a | | | | Abstract
| Thiocapsa roseopersicina, High Potential Iron Sulfur Pro tein (HIPIP), Phototrophic Bacteria High potential iron sulfur protein (HIPIP) from the purple sulfur bacterium Thiocapsa roseopersicina was iso lated in the oxidized and reduced form by DEAE-and Sephadex column chromatography (best purity index A 282 nm red JA 385 nm red. = 3.78). The enzyme contains non-heme iron and acid-labile sulfide in an equimolar ratio. The enzyme shows no aconitase activity. | | | |
Reference
| Z. Naturforsch. 35c, 150—153 (1980); received August lO/October 19 1979 | | | |
Published
| 1980 | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0150_n.pdf | | | | Identifier
| ZNC-1980-35c-0150_n | | | | Volume
| 35 | |
| 30 | Author
| BryanP. Cooper, FranziskaE. Baumgarten, Ahlert Schmidt | Requires cookie* | | | Title
| | | | | Abstract
| Adenylylsulfate, 3'-Phosphoadenylylsulfate, Adenosine 5'-monophosphoramidate, 3'-Phosphoadenosine 5'-mono-phosphoramidate, Ammonia | | | |
Reference
| Z. Naturforsch. 35c, 159—162 (1980); received October 181979 | | | |
Published
| 1980 | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0159_n.pdf | | | | Identifier
| ZNC-1980-35c-0159_n | | | | Volume
| 35 | |
| 31 | Author
| C. Sauer, U. Schwabe | Requires cookie* | | | Title
| M ethod for the Selective 2 '-0 -S u b stitu tio n o f N ucleosides | | | | Abstract
| This paper presents a new method for selective reactions o f predetermined sugar hydroxyls o f nucleosides. Suc-cinylated nucleosides were investigated as examples for the use of the cyclic phosphate group for protecting purposes. Starting from cyclic AMP the 2'-0-group was selectively succinylated yielding 93% 2'-0-succinyl cyclic AMP. The cyclic phosphate was enzymatically dephosphorylated in a one step procedure under neutral conditions and 2 '-0 -suc-cinyl adenosine containing a small amount o f the 3'-0-isomer was produced in 91% yield. When establishment of equilibrium of the 2'-0-and 3'-0-isomers was allowed, 54% yield of crystallized 3'-0-succinyl adenosine was prod uced. The results suggest that the easily accessible cyclic monophosphates are good protecting groups for the pro duction of nucleoside derivatives, especially at the 2 '-0 -position under neutral conditions. | | | |
Reference
| Z. Naturforsch. 35c, 163—167 (1980); received June 15/September 21 1979 | | | |
Published
| 1980 | | | |
Keywords
| Cyclic AMP, Enzymatic Synthesis, Cyclic Phosphate as Protection Group, 2'-0-Succinyl Adenosine, 2'-0-Substitu-tion o f Nucleosides | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0163_n.pdf | | | | Identifier
| ZNC-1980-35c-0163_n | | | | Volume
| 35 | |
| 32 | Author
| Bemd Schulz-Harder, Claudia Kiicherer | Requires cookie* | | | Title
| in Saccharomyces cerevisiae | | | | Abstract
| The ribosomal ribonuclease of yeast is induced after a withdrawal of glucose. Cycloheximide inhibits the synthesis of the enzyme under conditions of induction but antimycin shows no effect. Hence, the increase of the ribonuclease activity during growth of yeast is due to newly synthesized enzyme, and the induction does not depend on respiration. | | | |
Reference
| Z. Naturforsch. 35c, 168—170 (1980); received February 13/September 5 1979 | | | |
Published
| 1980 | | | |
Keywords
| Yeast, Ribosomes, Ribonuclease, Cycloheximide, Antimycin | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0168_n.pdf | | | | Identifier
| ZNC-1980-35c-0168_n | | | | Volume
| 35 | |
| 34 | Author
| K. H. Am Dorf, K. Kirschfeld | Requires cookie* | | | Title
| "Prebumps" : Evidence for D oub le-H its at Functional Subunits in a Rhabdomeric Photoreceptor | | | | Abstract
| In fly photoreceptors the latency of "bumps" due to single photon absorption is in the mean 6 0 -7 0 (± 2 0) ms (10 °C). With increasing stimulus intensities first the am plitude of the receptor potential increases without shorten ing of the latency; with still higher intensities the latency is reduced also. The first reduction occurs if neighboured microvilli are simultaneously hit by one light quantum each or if individual microvilli are hit by two quanta. Such "double hits" lead to a discrete reduction in latency which is manifested as a "prebump". | | | |
Reference
| Z. Naturforsch. 35c, 173—174 (1980); received October 15 1979 | | | |
Published
| 1980 | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0173_n.pdf | | | | Identifier
| ZNC-1980-35c-0173_n | | | | Volume
| 35 | |
| 35 | Author
| H. Newesely, R. Hosemann, B. U. Ther | Requires cookie* | | | Title
| Kollagen-Einschlußverbindungen Inclusion Compounds of Collagen | | | | Abstract
| Small angle X-ray diagrams o f native collagen o f rat tail treated with phospho tungstic acid or mercury chloride or cobalt-and uranyl-nitrate, osmiumoxide or hydroxy apatite show the same characteristic new reflections and reflection lines. The only remarkable difference exists between fibers treated under stress or relaxed. These experiments give new evidence for the paracrystallini-ty of collagen. More than 1 0 0 parallel aligned ca. 40 A thick octafibrils consist o f 670 A long micro paracrystals with 5 ca. 25 A thick soft segment layers. In these soft segments the holes o f the octafi brils build up a lattice o f vacancies with lattice cells o f 38,5x35x135 A3 length. The above mention ed molecules penetrate from the lateral sides through the soft segments into these vacancies build ing up complexes with peptide groups of collagen. Under stress only a small amount o f vacancies is occupied, statistically distributed over the vacancy-lattice, because the soft segments of the octa fibrils are constricted. Without stress about 10 to 25% o f the octafibrils within one paracrystal are filled up with sediments in the soft regions. With increasing precipitation finally 500 A long nee dles are formed of the inclusive material as detected by Höhling with the electron microscope in collagen of turkey tendon. The importance o f the paracrystalline collagen model is emphasized to understand the biological process like the mineralisation o f collagen and ^-keratin in organism or the activity of bone apatite in exchanging calcium ions. | | | |
Reference
| Z. Naturforsch. 35c, 177—187 (1980) | | | |
Published
| 1980 | | | |
Keywords
| Microparacrystals, Calcification, Octafibrils, Hydroxyl Apatite, Collagen Inclusion Compounds | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0177.pdf | | | | Identifier
| ZNC-1980-35c-0177 | | | | Volume
| 35 | |
| 36 | Author
| Heinz Rupp, K., Jozef Verplaetse, Rene Lontie | Requires cookie* | | | Title
| Binuclear Copper Electron Paramagnetic Resonance Signals of a-Methemocyanin of Helix pomatia | | | | Abstract
| The binuclear electron paramagnetic resonance signals o f a-methemocyanin o f Helix pomatia were investigated at liquid helium temperatures. These signals were completely eliminated by the addition of fluoride and enhanced in the presence o f chloride, which did not alter the saturation behavior. The triplet nature of the signal at g = 4.59 was confirmed by the low power-saturation. The addition of nitrite at pH 5.0 and 0° C yielded slowly and reversibly a seven-line half-field signal. On lowering the temperature the intensity of the triplet signals increased to the lowest tem perature reached 4.2 K, excluding a strong exchange coupling. | | | |
Reference
| Z. Naturforsch. 35c, 188—192 (1980); received September 18/November 17 1979 | | | |
Published
| 1980 | | | |
Keywords
| Copper, Electron Paramagnetic Resonance, Hemocyanin, Microwave Power Saturation | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0188.pdf | | | | Identifier
| ZNC-1980-35c-0188 | | | | Volume
| 35 | |
| 37 | Author
| S. Cannistraro, P. L. Indovina, L. Sportelli | Requires cookie* | | | Title
| Paramagnetic Species in /^-Thalassemic Sera: an ESR Study | | | | Abstract
| Homozygous beta thalassemic sera show an electron spin resonance (ESR) signal at g ~ 6 which is not present in normal and heterozygous sera. The signal arises from high spin heme groups exhibiting a departure from tetragonal symmetry toward rhombic. Binding by a serum protein is very likely responsible for such a distortion. In contrast with other authors' findings, we report that heme-human albumin complex shows a similar rhombic distortion. The observed ESR signal at g ~ 6 is then attributed to this complex. | | | |
Reference
| Z. Naturforsch. 35c, 193—196 (1980); received November 23 1979 | | | |
Published
| 1980 | | | |
Keywords
| Heme Groups, Albumin, ^-Thalassemia, Electron Spin Resonance | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0193.pdf | | | | Identifier
| ZNC-1980-35c-0193 | | | | Volume
| 35 | |
| 39 | Author
| Peter Proksch, Paul-G Erhard Gülz, H. Erbert Budzikiewicz | Requires cookie* | | | Title
| Phenylpropanoic Acid Esters in the Essential Oil of Cistus ladanifer L. (Cistaceae) | | | | Abstract
| Essential Oils, Cistaceae, Cistus ladanifer, Phenylpropanoic acid esters, NMR-and MS-Data Esters of phenylpropanoic acid with 2-phenyl-ethanol-1 and the homologue, 3-phenyl-propa-nol-1 as well as geraniol and dehydrogeraniol were found in the essential oil o f Cistus ladanifer. The isolation of these esters by chromatographic methods and structural elucidation by NMR and MS are described. | | | |
Reference
| Z. Naturforsch. 35c, 201—2 (1980); received December 27 1979 | | | |
Published
| 1980 | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0201.pdf | | | | Identifier
| ZNC-1980-35c-0201 | | | | Volume
| 35 | |
|
