Studio comparativo degli aminoacidi presenti negli estratti e negli idrolizzati di retina e di epitelio corneale di bue

Zusammenfassung Mittels Papierchromatographie wurde das Bild der freien Aminos?uren der Netzhaut und des Cornea-Epithels des Rindes untersucht und mit den Aminos?uren des Hydrolysats des gesamten Gewebes in Beziehung gebracht. Die Ergebnisse zeigen, dass das Bild der freien Aminos?uren ein charakteristischer Zug eines bestimmten Gewebes ist, obwohl er nicht ganz genau dessen Zusammensetzung an Aminos?uren wiedergibt.      

L'action antibiotique de la streptomycine étudiée au microscope électronique

Summary The authors have tried to observe, with the aid of the electron microscope, the effect of streptomycin on the morphology ofB. subtilis. This action is very swift and manifests itself by the appearance of cells with high turgescence (sporical forms, but not resistant), by extreme shrinkage of cytoplasm inside the cell-wall and by the extrusion of this cytoplasm from the cellular envelope.     

Accessibilité, solubilité et association,in situ,de la myosine

Summary myosinin situ is the more accessible to saline solutions the more finely the muscular substance has been divided, which implies its localization in structures difficult of access.This myosin exists in such structures in the form of a complex, the dissociation of which is effected by the saline solutions in proportion to their ionic strength.Fatigue does not modify the spatial accessibility of this complex but does modify its structures, so that, for some values ofp _H, solutions of equal ionic concentrations are less active on the substance of stimulated muscles than on that of normal ones.The myosin derived from that complex is much less homogenous in the Tiselius-Longworth apparatus than the myosin isolated from theWeber-Edsall myosin by fractionating with ammonium sulfate.Rabbits' muscles suddenly cooled by immersion in ice water give extracts similar to those of stimulated muscles.     

Sopra un caso particolare della superficie F 4 (3) di M. Noether

Summary The Noetherian surfaceF ₄ ⁽³⁾ , which is represented on a plane by a linear ³ system ofC ₉(A ₁ ³ A ₂ ³ A ₃ ³ A ₄ ³ A ₅ ³ A ₆ ³ A ₇ ³ A ₈ ³ A ₉ ² A ₁₀), possesses generally only one linear pencil of elliptic cubics. IfA _i (i=1, 2, , 9) are the basis points of aHalphen pencil ofC ₉,A ₁₀ is infinitely near toA ₉, and in this caseF ₄ ⁽³⁾ is a not trivial example of such a surface with two pencils of elliptic cubics.     

Über die Chemie des Enniatins

Summary Judging by the physical and chemical properties and bacterial spectra, the antibiotic substance, Enniatin, previously isolated from a strain ofFusarium by the authors, appears to be identical with that which was recently reported byCook et al. derived from another strain and designated by them as Lateritiin-I, although the reported empirical formulæ differ. Numerous physical and chemical characteristics of Enniatin and its degradation products are given, and, further, two relatedFusarium antibiotics, here designated as Enniatin B and C, are briefly described.

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Ausgeführt mit einem Beitrag aus den eidg. Arbeitsbeschaffungskrediten.     

La formule chromosomiale de la race bisexuée dePycnoscelus surinamensis L., comparée à celle de la race parthénogénétique

Summary The author has shown in 1945 that the thelytokous strain ofPycnoscelus surinamensis L. could not be a triploid one. This assumption is fully proved by the examination of the bisexual strain of which some individuals were obtained from Malaya. Both strains have the same chromosomic complement: 2N=37; 2N=38. In the male of the bisexual stock one may observe a lagging of a chromosome in the spermatogonial mitosis as well as in the second maturation divisions. We have here to do with a case of geographical parthenogenesis without polyploidy.     

Fasergabelung durch Auftreten lokalisierter Wachstumsbezirke

Summary The formation of forked fibres cannot be explained by the theories of sliding or of symplastic growth, while the theory of local apical growth of fibre ends accounts for all the actual facts observed in xylem and phloem fibres ofSparmannia africana. In this species cambium cells with a split end are found. These cells give rise to forked fibres, the forking point of which does not show any sliding growth, but remains on its original level. This evidence is undoubtedly a proof against the theory of sliding growth during fibre elongation inSparmannia.     

A new alarm pheromone (2-decen-1-yl-acetate) isolated from the stings ofApis dorsata andApis florea (Hymenoptera: Apidae)

Summary From sting extracts ofApis dorsata andA. florea, a substance was isolated which is active in alarm behaviour of both of these species but not ofA. mellifera andA. cerana. The active substance was identified as 2-decen-1-yl-acetate.     

Apparition d'une protéine nouvelle,la contractine,dans les extraits de muscles contractés

Summary When rabbit muscles are fatigued, the electrophoretic pictures of the extracts of these muscles are free from -myosin and show a large decrease in the amount of ₁ and ₂-myosin.When the muscles are contracted by monobromacetate or stimulated and fixed in a contracted state by liquid air, -myosin is very much decreased, ₁ and ₂-myosin disappears entirely, and a new component appears which is called contractin.The disappearance of the classical myosins and the appearance of this new protein in the extracts ofshortened muscles, may be of great interest in the study of the protein changes responsible for muscle contraction.     

Presenza di un principio antidiuretico nelle ghiandole salivari posteriori degli Octopodi

Summary Acetone and alcohol extracts of the posterior salivary glands ofOctopus vulgaris, Eledone moschata andEledone Aldrovandi contain a principle which strongly reduces the diuresis in hydrated rats.The antidiuretic principle is absent in all otherOctopus tissues as well as in the salivary glands ofOctopus macropus.It shows a high termostability and is strongly adsorbed by animal charcoal at any reaction.The salivary antidiuretic substance is not identical with the posterior pituitary principle nor with the other active substances found in the salivary glands of Octopoda.The injection of salivary extracts satisfactorily reduces polyuria and polydipsia in human diabetes insipidus.

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Le presenti ricerche sono state in parte sovvenzionate da un contributo straordinario del Consiglio Nazionale delle Ricerche.     

Über die Entstehung von Dehydracetsäure und ihren Analogen bei der Oxydation derα, γ, δ, ζ-Tetraketone mit Bleitetraacetat

Summary Oxidation of, , , -Tetraketones (I) with lead-tetraacetate yields dehydracetic acid and analogous compounds (IV). The reaction can be understood if one assumes that acylketenes (III) are formed as intermediates through the glycol-fission of the dienolic form II of the tetraketones.     

Le transaminasi negli stati di deficienza di cocarbossilasi

Summary Pyruvic and -ketoglutaric acid transaminase is increased in -ketoacidosis caused in guinea pigs and rats by cocarboxylase deficiency (avitaminosis C, alloxan diabetes). Fructose administration not only normalizes the increased concentration of ketoacids and the decreased cocarboxylase activity, but also the increased amount of transaminase. It is suggested that in -ketoacidosis from transaminable ketoacids the increased transaminating activity might be substitute for reduced cocarboxylase activity.     

Il tenore di acido desossiribonucleico negli eritrociti diAnas Platyrhynchos,Cairina moschata e dei loro ibridi diretti e reciproci

Summary The desoxyribonucleic acid content in nuclei of erytrocytes inAnas platyrhynchos, Cairina moschata and their direct and reciprocal hybrids is studied by the quantitative method. A significant difference was found between the amounts in the two parental species. The hybrids reveal an irregularity in behaviour of their means and distribution of contents. This seems to be dependent on their origin and sex. These findings are discussed and critically compared with other data from the literature, concerning the desoxiribonucleic acid content and chromosome-characteristics.

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Lavoro eseguito con un contributo del C.N.R. Il materiale è stato raccolto alla Stazione Sperimentale di Pollicultura di Rovigo, diretta dal prof.A. Taibel, al quale devo i più vivi ringraziamenti, anche per le utili indicazioni ed i consigli forniti.     

Oberflächenspannung und Schallgeschwindigkeit

Summary The preceding empirical relation was found between the surface tension of liquids, the specific weight of liquids, and the velocity of sound:=6.3 · 10^{–4 3/2}. In place of the vèocity of sound can be used, with suitable changes in the equation, the compressibility or, in the case of solid substances, the elasticity of the material in question. The range of validity of this relation is so large that it is possible by means of it to calculate the surface tension of solid substances and of gases.     

Prévention de l'œdème aigu expérimental du poumon par un antihistaminique de synthèse dérivé de la thiodiphénylamine

Summary N-dimethylamino-2-propyl-1-phenothiazine (3277 R.P.) has been shown to possess an antihistamine and anti-anaphylactic activity that is unequaled up to now.Hypodermic preventive injections regularly protect the rabbit against acute pulmonary dema provoked by epinephrine. An intravenous injection of this substance made 3 to 4 minutes after an intravenous injection of epinephrine, that is at the time an acute pulmonary dema seems to begin, is able to prevent fatal consequences.The hypertensive action of adrenaline, and the resulting dilatation of the heart is not prevented by the phenothiazine derivative.The antihistamine substance seems to exercise an effect on capillary permeability when preventing acute pulmonary dema.

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B. N. Halpern, Arch. int. Pharmacol. Thér.74, 314 (1947); J. Allergy18, 263, 272 (1947).     

Passaggio di nucleoli attraverso la membrana nucleare negli ovociti in accrescimento diPatella coerulea L. (Moll. Gast. Pros.)

Summary The author has found in increasing ovocytes ofPatella coerulea, particularly in the nuclear membrane, a real passage of small nucleoli from the nucleus to the cytoplasm. Thus not all the nucleoli which appear little by little in the nucleus are amphinucleoli.     

Etude électrophorétique des variations de composition d'extraits musculaires de Lapin sous l'influence de la fatigue et de la contracture par le monobromacétate de soude

Summary Rabbit muscular globulins soluble between the ionic strengths 0.15 and 0.35 are, in an almost native state, the and myosins ofDubuisson. The extractability of both, and, by salt solutions is greatly reduced when the rabbit muscle has been stimulated to exhaustion or poisoned with the sodium salt of monobromacetic acid till a state of rigor is obtained. This reduction however does not proceed in an absolutely similar way for and, indicating probable functional differences between these two myosins. The other soluble muscular proteins are practically not affected, as far as the method permits this to be assertained.     

Osservazioni preliminari,chimiche e farmacologiche,sulla murexina

Summary (1) Murexine, a new choline derivative found in the hypobranchial body ofMurex trunculus, Murex brandaris, andTritonalia erinacea, was isolated as picrate, picrolonate, styphnate, flavianate, and reineckate. Some preliminary characteristics of these salts are given.(2) The murexine content of the median zone of the hypobranchial body ofMurex trunculus is extremely high: murexine picrate equivalents of 45–70 mg per g fresh tissue are commonly observed.(3) Murexine manifests intense nicotinic and curariform actions, but is practically wanting in any muscarinic activity.The central nervous system is strongly affected by the substance: at first stimulation seems to prevail, but later on, with larger doses, a deep depression regularly develops.In decapitated cats and dogs murexine causes a significant rise in blood pressure, which is due, at least partially, to a liberation of epinephrine from the adrenal medulla and from the adrenergic nerve terminals.On the enucleated eye of frogs andOctopoda the substance acts to cause mydriasis and expansion of the iris chromatophora.

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V. Erspamer eF. Dordoni, Arch. int. Pharmacodyn.74, 263 (1947).     

Mitocondri,zone del Golgi e globuli vitellini negli ovociti in accrescimento diPlanorbis corneus L. (Moll. Gast. Polm.)

Summary The authors observed, in the oocytes ofPlanorbis corneus, that the yolk globules are formed from the mitochondria, which first swell up and then are filled with proteic particles (of a probably ribosomal nature). Such a process is in relation to the formation of the Golgi zones.     

Trasmissione del tumore di Yoshida con estratti acellulari del medesimo

Summary The authors demonstrate the transmissibility of the tumour of Yoshida by means of definitely acellular, tumoural extracts. Neoplasia occurred in 11 out of 12 new-born mice i.p. inoculated as above. It is noteworthy that the neoplasia developed not only ascitic but also solid (nodes and tumoural nodules) prevalently at pulmonar level. Derived tumoural ascites are transmissible to the adult rat.