Darstellung und physikochemische Charakterisierung der Peptidketten des Tabakmosaikvirus

Summary Highly purified tobacco mosaic virus was split by different methods, the ribonucleic acid removed and the size of the protein sub-unit determined by sedimentation and diffusion. The value for the molecular weight of a polypeptide chain of the tobacco mosaic virus was calculated to be 17–18 000.     

Elektronenoptische Untersuchungen des Hauptstrom-Rauchkondensats der Partikelphase des Cigaretten- und Cigarrenrauchs

Summary Report on a method to produce, without refrigeration and solvents, a tobacco smoke condensate of the tobacco main-stream smoke of the particulate phase. Identification obtained by the electron fine beam diffraction of crystals in the sediment of the smoke condensate of cigarettes and cigars.

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Wissenschaftlicher Gast am Institut für Elektronenmikroskopie des Fritz-Haber-Instituts der Max-Planck-Gesellschaft.     

Untersuchungen zur Klärung der Funktion des Reissnerschen Fadens. In-vitro-Bindung von Noradrenalin,Adrenalin und Serotonin

Summary The glycoprotein of Reissner's fibre is able to bind norepinephrine, epinephrine and serotonin. Bound amines can be demonstrated at the RF, even after washing with artificial cerebrospinal fluid for some, hours. It is discussed whether it is a function of the RF to remove substances, for instance biogenic amines, from the cerebrospinal fluid.     

Experimentelle Untersuchungen zum Wirkungsmechanismus der beiden entwicklungsphysiologisch aktiven Fraktionen des «Gehirnhormons» der Insekten (Aktivationsfaktor I und II) auf die Prothoracaldrüse

Summary 2 prothoracotropical factors (activation factor I and II) have been obtained by gel filtration techniques from brains and corpora cardiaca of the cockroachPeriplaneta americana. In contrast to activation factor II, activation factor I caused significant influence of RNA synthesis. The RNA pattern of prothoracic glands stimulated by activation factor I as demonstrated by polyacrylamide gel electrophoresis consists of different kinds of RNA. Short time incubation revealed effects on sRNA synthesis, while long time incubation demonstrated predominantly increase of ribosomal RNA synthesis. Measurements of the membrane potential of the prothoracic gland cells of the wax mothGalleria mellonella indicated an increase by activation factor II; activation factor I was without any visible effect. Our results demonstrate for the first time that the two activation factors induce different effects at cellular level.

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Für technische Unterstützung danken wir FräuleinA. Zinsser und FrauR. Meissner.

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Durchgeführt mit Mitteln des Ministeriums für Wissenschaft und Technik und mit Unterstützung durch die Sächsische Akademie der Wissenschaften zu Leipzig.     

Pharmakologische Untersuchungen bei Thiaminmangel I. Änderungen des Katecholamingehalts im Gewebe

Summary (1) The increased tissue catecholamine level of the thiamine deficient rat was shown in the atrium, the ventricle, the brain cortex and in the spleen but not in the brain stem and the adrenal gland. (2) The increased response to tyramine of the thiamine deficient heart is most probably due to the high catecholamine level caused by thiamine deficiency. (3) The increased catecholamine content in the thiamine deficient rat does not result from the increased pyruvic acid.

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Herrn Professor Dr.F. Th. von Brücke zum 60. Geburtstag im Januar 1968 gewidmet.     

Histochemische Untersuchungen zur Natur der Cytoplasma-Einschlüsse des Lungentumors der Maus

Résumé Dans une étude histochimique on a montré que les inclusions cytoplasmiques des tumeurs pulmonaires de la souris (Klärner etGieseking) contenaient une polysaccharide neutre jointe à l'acide ribonucléique. Les résultats ont été discutés au sens d'une hypothèse virale.     

Zum Schlüpfprozess bei Fischen: II. Gewinnung und Charakterisierung des Schlüpfsekretes bei der Regenbogenforelle (Salmo gairdneri Rich.)

Summary A method is described to get the secrete of the hatching glands together with the perivitelline fluid by stimulating the eggs ofSalmo gairdneri with dissolved gaseous nitrogen in various buffers. Characterizing this fluid by various methods there could be shown some enzymes of those a proteinase alone seems to be the really hatching enzyme.Der Deutschen Forschungsgemeinschaft sei für finanzielle Unterstützung gedankt.     

Experimentelle Untersuchungen zur Steigerung der Laktatdehydrogenase-Aktivität des Harnes

Summary In rat urine, determinations of lactate dehydrogenase (LDH) activity were performed. Normal values ranged between 94 and 140 mU/24 h urine specimens. Experimentally induced renal damage (anaphylactic or anaphylactoid shock; administration of sodium tetrathionate; potassium depletion) provoked a statistically significant increase in urinary LDH-activity. The 3 mechanisms by which such an increase might occur are briefly discussed.     

Disk-elektrophoretische Untersuchungen der Serumproteine europäischer Eschsen der Familien Anguidae und Lacertidae

Summary Serum proteins ofLacerta v. viridis, L. v. meridionalis, L. trilineata, L. agilis, L. vivipara, L. taurica, L. muralis, Ophisaurus apodus, andAnguis fragilis were separated by polyacrylamide disc electrophoresis. Among the lacertids,Lacerta viridis andLacerta trilineata show greater similiarities.Ophisaurus apodus andAnguis fragilis are characterized by praealbumins.     

Die Verteilung von Noradrenalin und Adrenalin im Herzen der Katze,des Kaninchens und der Ratte

Summary The concentration of noradrenaline in different parts of the heart was estimated in cats, rabbits, and rats. In each heart, the concentration of noradrenaline was much higher in the right atrium than in the left atrium and higher in the right ventricle than in the left one.     

Die Wirkung des Toluidinblaus und der Thrombokinase auf den Vorgang der Thrombininaktivierung

Summary The disappearance of thrombin—formed in the blood, or added to serum-follows a manomolecular reaction-type. Heparin increases the reaction-velocity of this thrombin-inactivating process.Our investigation established that toluidine blue or kinase, which, according to the literature, bind heparin, strongly reduce the speed of thrombin-inactivation too. Therefore the heparin-binding capacity of these substances is also manifested in the decrease of thrombin-inactivation.     

Zum Proliferations-Stoffwechsel der Rattenleber nach Teilhepatektomie. Autoradiographische Untersuchungen mit3H-Cytidin,-Phenylalanin und -Thymidin

Summary During the first wave of parenchymal liver regeneration in adult rats after partial hepatectomy, the cellular synthesis and migration of RNA and the metabolism of protein were studied by autoradiography following an injection of³H-cytidine or³H-l-phenylalanine and double injections of 1 of these precursors +³H-thymidine. The following results were obtained: the synthesis and migration of RNA and the metabolism of protein are enhanced under these conditions of proliferation. In spite of this, the relation of metabolic activity in nucleolus, karyoplasm and cytoplasm remains constant. By double injection techniques it is proved that no differences exist in migration of RNA into the cytoplasm and cytoplasmic protein synthesis between cells with or without DNA synthesizing nuclei.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Motive und Probleme der Arithmetisierung der Mathematik in der ersten Hälfte des 19. Jahrhunderts — Cauchys Analysis in der Sicht des Mathematikers Martin Ohm

Ohne Zusammenfassung Vorgelegt von C. J. Scriba     

Membrandepolarisation der Muskelfasern des Öffnermuskels des Flusskrebses auf Nervenreiz und Kaliumapplikation

Summary Three groups of fibres with different EPSP were differentiated in the claw-opening muscle of crayfish. Small and late depolarization of the deep fibres was observed on application of 3–4 times the normal concentration of KCl.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Vergleichende Elektronenmikroskopie reiner DNS und der DNS des Bakteriennukleoids

Summary The behaviour of pure isolated DNA towards the conditions of fixation and dehydration—prior to ultrathin sectioning—has been studied and compared with the behaviour of the DNA-plasm of the bacterial nucleus. It is found that those conditions which produce coarse coagulation of the free DNA also produce electron opaque bodies of variable aspect inside the bacterial nucleus. The coagulation figures obtained in both situations are very similar. This is a further direct evidence in favour of the view that the bacterial nucleus is an assembly of fine DNA-containing fibrilla in a highly hydrated plasma.     

Geschwindigkeit der imidazolkatalysierten o-Acetylierung von Derivaten und Peptiden des Serins und Threonins

Summary o-Acetylation of cyclo-his-ser and cyclo-histhr in acetic acid/acetanhydride proceeds via intermolecular, and in the case of 4-hydroxyethyl-imidazole via intramolecular, acyl transfer. The highest rate of acetylation is observed with 4-hydroxyethyl-imidazole, and the most effective catalyst in the case of intermolecular acyl transfer is imidazole; derivatives of imidazole are less effective. Derivatives and peptides of serine are generally more reactive than those of threonine.     

Untersuchungen über Ultrastruktur und Aminosäurenzusammensetzung der Eischalen vonNatrix natrix

Summary The ultrastructures of eggshells ofNatrix natrix and the membrana testacea ofGallus gallus dom. are very similar, with the exception of cavity systems which only exist in eggshells of snakes (ringsnake) but not in the membrana testacea of birds. In the sheath of the fibres ofNatrix natrix, a positive ruthenium redreaction indicates the presence of mucopolysacharides, or proteoglycans. The eggshells ofNatrix natrix contain a high proportion of proline, but also of cystine, histidine and arginine. The high proline content is discussed with regard to the properties of poly-l-proline. Presumably proteins similar to collagen exist in eggshells ofNatrix natrix.     

Infrarotspektroskopische Untersuchungen an Desoxyribonukleinsäuren,ihren Derivaten und Analoga. VIII. Ermittlung der nichtebenen NH-Deformationsschwingungen

Summary The NH out-of-plane deformation and the NH₂ wagging vibrations of base-pairing models of DNA and related model substances in the solid state are assigned by deuteration shifts, cooling shifts, and shifts caused by the complementary base-pairing. The sensitivity of the frequencies of these vibrations to variations of the hydrogen bond strength may be useful to follow conformational changes of nucleic acids.     

Untersuchungen zur Organotropie der krebserzeugenden Wirkung des N-Nitroso-N-methyl-Harnstoffes (NMH) an Ratten

Summary Methyl-nitrosourea, an unstable nitrosamide, exhibits a resorptive cancerogenic effect after shorttermed oral administration of high doses (4 times 40 mg/kg body weight). Induction time and localization of the observed tumours depend, among other things, on the dose and the pH of the cancerogen solution and on the age of animals.