Über den Einfluss desd,l-Methioninsulfoximins auf den Eiweißstoffwechsel bei Erbsen

Summary The influence of thed,l-Methioninesulphoximine on the nitrogen metabolism of germinating seeds has been studied on peas. It has been shown thatd,l-Methioninesulphoximine, even at low concentrations, inhibited the germination of seeds and produced a decrease of growth of the roots. The inhibited germinating seeds contained less non-protein-nitrogen and less asparagine than the control plants. On the basis of the experimental results,d,l-Methioninesulphoximine could be considered as an inhibitor of proteolysis.     

Über ein Chromoplastin aus reifenden Tomaten

Summary (1) By precipitation with ammonium sulfate, streptomycin, or calcium salts, we obtained from the pulp of tomatoes a substance containing carotinoids. The behaviour of this substance was analogous to that of chloroplst-substance and to that of animal cytoplasmatic nucleoproteins. Like these it contains proteins, lipids, and very probably nucleic acids. We regard this substance as achromoplastine.(2) Experiments with slices of green tomatoes show that the changing over of the chlorophyll content into the carotinoid content is inhibited by the presence of streptomycin.(3) Streptomycin inhibits the formation of chlorophyll in etiolated separated cabbage leafs, just as this drug inhibits the formation of chlorophyll in growing seeds.(4) The development of anthocyanides is not influenced by streptomycin.     

Die durch animalische Mucoproteine verursachte Wachstumshemmung

Summary Anti-growth activity of animal mucoproteins on germinating seeds ofLupinus albus was tested; the inhibition with plasma mucoprotein was statistically significant. The inhibition with urine mucoprotein according toAnderson was the most effective.     

Die Wirkung von Adenin und Urazil auf das Wachstum vonB. coli commune

Summary The growth ofBacterium coli commune in culture-medium afterFriedlein containing glucose was controled by photometry. Addition of uracil hastens the growth slightly, addition of adenin delays it. The curve of growth with adenin shows two maxima similarly as the primary and secundary effect after irradiation of biological material by ultrashort rays. As known the irradiation of nucleic-acids sets in partial freedom purins and pyrimidins. These are changed again by intense irradiation. The news products of irradiation have probably also biological influences.     

Untersuchungen über die Wirkung von Kinetin auf Kallus und Tumoren bei Organkulturen vonNicotiana glauca,N. langsdorffii und deren amphidiploiden Bastard

Summary In leaf cultures ofNicotiana glauca, N. langsdorffii, and their amphidiploid hybrid, callus growth or tumor formation is enhanced by kinetin, depending on its concentration. Of the 2 species and their hybrid, maximum response was found in the hybrid, less inN. glauca, the slightest response being found inN. langsdorffii. These facts confirm the earlier finding of a connection between callus-forming potency inN. glauca and tumor formation in its hybrid.

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Den Herren Prof. Dr.G. de Lattin (Zoologisches Institut der Universität des Saarlandes) und Prof. Dr.F. Anders (Genetisches Institut der Justus Liebig-Universität, Giessen) bin ich für die Förderung dieser Arbeit zu grösstem Dank verpflichtet.     

Der Eigenartige Einfluß Witelos auf die Entwicklung der Dioptrik

Summary Witelo's Perspectiva, which was printed three times in the sixteenth century, profoundly influenced the science of dioptrics until the Age of Newton. Above all, the optical authors were interested in the so-called Vitellian tables, which Witelo must have copied from the nearly forgotten optical Sermones of Claudius Ptolemy. Research work was often based on these tables. Thus Kepler relied on the Vitellian tables when he invented his law of refraction. Several later authors adopted Kepler's law, not always because they believed it to be true, but because they did not know of any better law. Also Harriot used the Vitellian tables until his own experiments convinced him that Witelo's angles were grossly inaccurate. Unfortunately Harriot kept his results and his sine law for himself and for a few friends. The sine law was not published until 1637, by Descartes, who gave an indirect proof of it. Although this proof consisted in the first correct calculation of both rainbows, accomplished by means of the sine law, the Jesuits Kircher (Ars Magna, 1646) and Schott (Magia Optica, 1656) did not mention the sine law. Marci (Thaumantias, 1648) did not know of it, and Fabri (Synopsis Opticæ, 1667) rejected it. It is true that the sine law was accepted by authors like Maignan (Perspectiva Horaria, 1648) and Grimaldi (Physico-Mathesis, 1665), but since they used the erroneous Vitellian angles for computing the refractive index, they discredited the sine law by inaccurate and even ludicrous results.That even experimental determinations might be unduly biased by the Vitellian angles is evident from the author's graphs of seventeenth century refractive angles. These graphs also show how difficult it was to measure such angles accurately, and how the Jesuit authors of the 1640's adapted their experimental angles to the traditional Vitellian ones. Witelo's famous angles, instead of furthering the progress of dioptrics, delayed it. Their disastrous influence may be traced for nearly thirty years after Descartes had published the correct law of refraction.

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Vorgelegt von C. Truesdell     

La nature de la substance minérale de l'os

Summary In answer to objections put forward byBrandenberger andSchintz against their theory concerning the chemical nature of bone salts, the authors afford supplementary evidence about the real crystalline and chemical entity of hydrated tricalcium phosphate. According to the conditions, the precipitate contains either dicalcium phosphate or lime and this affects the nature of the product obtained by calcination.The mineral bone substance is not a hydroxylapatite because it turns either to carbonato-apatite or oxyapatite according to carbon dioxide being kept or not in the crystal lattice. The X-ray patterns of those two apatites are undoubtedly different.

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Réponse à une note deE. Brandenberger etH. R. Schinz, Exper.4, 59 (1948).     

l-Methionin als Regulator der Spannung von Collagen

Summary Collagen fibres produce tension in hypermolar salt solutions such as 5M NaClO₄. This tension can be increased by formaldehyde 0.035M (or more). These reactions are reversible in 0.15M NaCl and can be repeated many times.l-Methionine in 0.01M solution inhibits the reversal. It is supposed that this effect is caused by inhibition of the aldol-aldimin reaction which restitutes the crosslink in the collagen fibre.     

Chlorophyll stability index,a suitable criterion for rapid screening of tree provenance in arid zones

Zusammenfassung Als Mass für die Herkunft einer Baumrasse wird der Chlorophyllstabilitätsindex verwendet. FürEucalyptus camaldulensis steht dieser in Korrelation mit der Überlebensrate der Keimlinge und mit der jährlichen Niederschlagsmenge am Herkunftsort.

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The authors wish to thank the Australian Forestry Authorities for providing seeds of different provenances ofE. camaldulensis, and to Dr.P. C. Raheja and Mr.C. P. Bhimaya for providing the necessary facilities for the study.     

Columnar cells of the parietal layer of Bowman's capsule and their relationship with the sexual cycle in normal female mice

Summary The tubule-like cells (TLC) are present also in the parietal layer of the Bowman's capsule of the renal corpuscles in normal female mice kidney. These cells are morphologically similar to the cells of the proximal convoluted tubule. Further, significant variations of the TLC were present according to the phase of the sexual cycle.The authors are greatly indebted to Dr.Pietro Motta for his valuable suggestions and criticism, and to Mr.Isidoro Vittori for his valuable technical assistance.     

The decrease in seed germination ofStriga hermonthica in Benin in the course of the rainy season is due to a dying-off process

Germination rate and viability ofStriga hermonthica seeds in the field in the Republic of Benin decreased steadily in the course of the rainy season. The percentage of germinating seeds decreased from 82% on April 13, 1993 to 16% on October 13, 1993. The percentage of viable seeds, according to the tetrazolium colour test, decreased in the same period from 90% to 15%. In the subsequent rainy season these values further decreased and it was concluded that the seeds do not enter a stage of secondary dormancy. This implies that if host plants (including wild hosts) are consistently kept away from infested fields for one or two year periods, this will lead to a dramatic decrease in the number of viableS. hermonthica seeds in the soil.     

Molekulargewichtsbestimmung von Kalbsherzmyosin

Summary Sedimentation and diffusion coefficients, partial specific volume, intrinsic viscosity, ATP-ase activity and molecular weight of cardiac myosin from calf hearts were determined. The values agree well with the results ofMueller et al.⁴ for cardiac myosin of the dog, and are not essentially different from values reported for skeletal myosins.¹      

Über die Gestalt von Fadenmolekülen in Lösung

Summary Some arguments put forward byG. Bier in a recent article in order to supportH. Staudinger's assumption that chain molecules in solution should behave like straight rigid rods are examined. It is shown that the assumptions made byG. Bier are largely arbitrary. The main argument is the assumption that the C-C-bond in long chain molecules should not show any rotation. As far as this point is concerned, attention is drawn to some recent publications showing that the viscosity of shape of chain molecules can be determined by experiment (specific viscosity and double refraction of flow at high velocity gradients). According to these determinations the time necessary for a complete change of shape, using partially free rotation, is of the order of 10^–5–10^–3 seconds for molecules like nitrocellulose or polystyrene up to degrees of polymerization of several thousands and for viscosities of the solvent of the order of 10^–2 poises.     

Beziehungen zwischen laccase- und peroxidaseartigen Isoenzymen von Basidiomyceten

Summary Phenoloxidases of 30 wood-rotting fungi were separated by isoelectric focusing. It turned out that apparent peroxidasic activity of the crude extracts of certain species is not necessarily atributable to peroxidases but to the special properties of certain laccase isoenzymes, which may be uninfluenced, inhibited, or activated by H₂O₂. These interactions differ in certain species for intra- and extracellular forms of the same isoenzyme.

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Wir danken den technischen Mitarbeitern unseres Lehrstuhls, besonders FräuleinK. Kuprat, für ihre Unterstützung und der DFG für Sachmittel.     

E- und I-Netzhäute von Urodelen

Summary Two representatives of the same urodele family (Salamandridae) demonstrate in their electroretinograms 2 different types of light response. These 2 types correspond well withGranit's concept of E-retinae and I-Retinae.     

Die Wirkung von synthetischem Oxytocin (Syntocinon) und Acetazolamid auf die Ausscheidung von Wasser,Natrium und Kalium

Summary Changes in water, sodium, and potassium excretion following administration of synthetic oxytocin (Syntocinon)—alone or in combination with acetazolamide— resemble the changes that occur after an equivalent dose of neurohypophysial extract containing oxytocin. Since the action of Syntocinon on water and sodium excretion is manifest when carbonic anhydrase in kidney tissue is fully inhibited by acetazolamide, it may be assumed that the mechanism whereby Syntocinon increases sodium excretion is independent of carbonic anhydrase. Oxytocin does not affect ultrafiltration in the glomeruli (Krause ⁴) and would therefore appear to modify the reabsorption or excretion process in the tubuli.     

Reinigung von F-antigen

Summary F-antigens are glycoproteins with s ₂₀ ^c , 0.1M NaCl=5.4 and a main component in SDS-polyacrylamide of molecular weight of 40,000. Separation of F-antigens is described; with the methods used they are indistinguishable.

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Arbeit mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung (Kredit Nr. 5254.3). Herrn Dr.H. Mosimann danke ich für die Hilfe bei der analytischen Ultrazentrifugation, Frl.U. Kohler für Mitarbeit und Herstellung der Skizzen.     

Zur Pharmakologie von Convallatoxol,zugleich ein Beitrag zur pharmakologischen Strukturanalyse von g-Strophanthin

Summary A report is given of the positive inotrope effects of genins and glycosides with one methyl or aldehyde or carbinol group in the C₁₀ atom of the steroid stage, and of the influence of thel-rhamnose compared withd-digitoxose andd-cymarose. A structure analysis of the ouabain and convallatoxol is derived from the differences in the degree of abolition of the acute cardiac damage in the experiments.     

Über den Einbau von Dipeptiden in Ergotoxin-Alkaloide

Summary l-Valyl-l-leucine-U-¹⁴C,l-valyl-l-proline-U-¹⁴C-lactam andl-leucyl-l-proline-U-¹⁴C-lactam were administered to submerged cultures of an ergotoxine-mixture-producing strain ofClaviceps purpurea. The added dipeptides were split by the fungus into the corresponding amino acids prior to incorporation. Apparently dipeptides are no immediate precursors for the peptide side-chain of ergotoxinealkaloids.     

Altersbedingte Abnahme von Kreatinphosphat und Änderungen der Adeninnukleotide in der Skelettmuskulatur von Ratten

Summary The content of phosphocreatine and of the adenin nucleotides, ATP, ADP and AMP in the white skeletal muscle of rats of different ages has been determined.There is an age-dependent relation between the quantity of phosphocreatine and the ratio of ATP/ADP. Young rats contain relatively much phosphocreatine (up to 57%) and a high ATP/ADP ratio (mean 6.7) while old rats show less phosphocreatine (40.8%) and also a low ATP/ADP ratio (mean 2.2).

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M. Ermini dankt der Schweizerischen Akademie der Medizinischen Wissenschaften für eine Verlängerung seines Stipendiums undI. Szelenyi dankt für ein USA Forschungs-Stipendium an das Institut für experimentelle Gerontologie in Basel. Herrn Prof.F. Verzár sind wir für die Leitung dieser und weiterer Arbeiten zu Dank verbunden.