Showing papers by "University of Lausanne published in 1972"

“Ayahuasca,” the South American hallucinogenic drink: An ethnobotanical and chemical investigation

Abstract: The Sharanahua and Culina, small Indian tribes located in the southwestern Amazon basin, use a hallucinogenic drink for medicinal and social purposes. This decoction, called “Ayahuasca” in Peru, is prepared from Banisteriopsis Caapi stems and Psychotria sp. leaves. These plants have been botanically identified on the basis of voucher herbarium specimens and investigated for alkaloid content by means of a gas chromatography-mass spectrometry technique. A list of other occasional plant admixtures is given. Harmine, Harmaline, Tetrahydroharmine, Harmol and 6-Methoxytryptamine have been found in Banisteriopsis Caapi. Dimethyltryptamine, Monomethyltryptamine and 2-methyl-1,2,3,4-tetrahydro-β-carboline have been found in Psychotria viridis and Psychotria carthaginensis. Harmine, Harmaline, Tetrahydroharmine and Dimethyltryptamine have been found in the drink. Quantitative calculations show the amount of each alkaloid administered in the Ayahuasca drink.

The syn and anti Steric Course in Bimolecular Olefin‐Forming Eliminations

Abstract: Earlier evidence led to the view that in bimolecular olefin-forming eliminations the anti steric course is generally preferred over the syn. Recent experiments, however, show that in some common bimolecular elimination reactions, notably those involving onium bases, syn- and anti-eliminations proceed side by side, the former preferentially leading to the trans- and the latter to the cis-olefins.

Root cap and root growth.

Abstract: The caps of the roots of Zea mays (var. Kelvedon 33) are the source of a growth inhibitor system which also acts on the root elongation of Lens culinaris.

Studies on the formation of V3Ga and V3Si superconducting compounds by a new diffusion process

Abstract: In the present work, diffusion between vanadium and Cu-20 at.% Ga alloy and that between vanadium and Cu-20 at.% Si alloy were studied. An intermetallic compound, V3Ga, is formed easily by the selective diffusion of gallium from the Cu-Ga alloy to the vanadium. V5Si3 and V3Si are formed also by the selective diffusion of silicon from the Cu-Si alloy to the vanadium. Copper scarcely dissolves either in V3Ga, V5Si3 or V3Si. Copper is not effective for enhancing the formation of V3Si unlike the case of V3Ga. A large super-conducting critical current density, Jc, is obtained in the V3Ga formed at temperatures below 700° C while a much smaller Jc is obtained in the V3Si formed at 800° C. Changes in Jc due to the heat-treatment can be interpreted by the grain growth of the compounds.

On the Social Behavior in a Stable Group of Long-Tailed Field Mice (Apodemus Sylvaticus). Ii. Its Relations With Distribution of Daily Activity

Abstract: A group of three or four long-tailed field mice (Apodemus sylvaticus) living in a large terrarium was observed for three consecutive months. A comparative analysis of their social behavior and temporal distribution of activity shows that there was a simple direct correlation between the number of encounters and the amount of time two or more mice spent together at the surface of the terrarium. It also shows an alternation of social and asocial periods, each of those lasting one or several weeks. In a social period, encounters were frequent, the mice spent much time together and were rarely seen to be active alone. The individual activity patterns were concordant, which contributed to the high amounts of simultaneous activity and of encounters. But in an asocial period, encounters were scarce, little time was spent together and solitary mice were often seen; the socially top ranking animal restricted its activity to certain times of the day and the three other mice to other times of the day, which contributed to the low amount of simultaneous activity and to the low frequency of encounters.

Lymphadenitis with massive hemophagocytic sinus histiocytosis.

Abstract: Lymphadenitis with massive hemophagocytic sinus histiocytosis has been reported in patients with scleroma and in cervical lymph nodes of children without any known etiologic condition. Using electron microscopy, we conducted the present study on submandibular enlarged lymph nodes from a 6-year-old girl with this condition. Examination revealed marked dilatation of the sinusoids due to extensive sinus histiocytic proliferation. The most conspicuous feature is phagocytosis of blood cells, predominantly of lymphocytes, by histiocytes. Engulfment of granulocytes, plasma cells and plasma cell precursors is less significant. Erythrophagocytosis is rare. Initially, the phagocytosed cells appear well preserved. Eventually, however, the engulfed cells are completely digested. Hemophagocytosis is less pronounced in histiocytes of the pulp. The blood vessels contain an abundance of monocytes. It is concluded that histiocytes of the pulp and of the sinuses are derived from emigrated blood monocytes. Two main kinds of sinus histiocytes are distinguishable: One type exhibits only faintly staining cytoplasm. The second type shows striking eosinophilia of the cytoplasm having a tendency to giant cell transformation with one or multiple nuclei. Type 1 sinus histiocyte shows prominent hemophagocytosis. Phagocytic activity is less pronounced in type 2 sinus histiocyte which, ultrastructurally, exhibits long slender cytoplasmic processes like those described in epithelioid cells. The inflammatory nature of this condition is indicated by the profuse infiltration of the pulp by plasma cells which are thought to be connected with the production of humoral antibodies. This leads one to suspect that antibody-mediated opsonization of the ingested blood cells is responsible for the hemophagocytic process. However, it cannot be excluded that hemophagocytosis is merely the result of a nonspecific stimulation of the sinus macrophages by infectious organisms. The failure to demonstrate microorganisms is not incompatible, of course, with an infectious etiology. The organisms may be only briefly present at the time of initial infection supplying the stimulus for the primary process resulting in this peculiar inflammatory reaction.

Ichthyosis linearis circumflexa Comèl with Trichorrhexis invaginata (Netherton's Syndrom): an ultrastructural study of the skin changes.

Abstract: An electron microscopical study of skin from 2 patients with ichthyosis linearis circumflexa and trichorrhexis invaginata revealed a severe and localized disturbance of keratinization occuring at the keratotic border of figurate skin lesions. It is characterized by a marked decrease of the desmosome-tonofilament system, lack of membrane coating granules and keratohyalin, and the appearence of roundoval, electron dense bodies in the upper spinous layers. The result is a completely disorganized “stratum corneum”. We consider this unique keratinization disorder to be specific for this disease.

The tissue dynamics of heart morphogenesis. I. The phenomena of cell death. A. Identification and morphology.

Abstract: 1. The morphology and some histochemical aspects of spontaneous cell death associated with the development of the chick embryo heart were studied. 2. The degenerative phenomena in the bulbar cushions on the 4th to 5th day of incubation, as based on hematoxylin-eosin staining, were ascertained by means of methyl green-pyronine staining, PAS, Feulgen and acid phosphatase reactions, supravital Nile blue sulphate and neutral red stainings as well as electron microscopy. 3. The degenerating, dying or dead cells were found to be Feulgen-positive. Some were PAS-positive. The staining pattern with methyl green-pyronine indicated DNA and RNA materials. 4. The macrophages appearing on the 5th day of incubation in bulbar cushions stained supravitally with Nile blue sulphate and neutral red, and large quantities of acid phosphatase could be demonstrated. 5. The electron microscope studies confirmed increased autophagic activity at the begining of degeneration and the appearance of macrophages in the later stages. 6. With increasing embryonal age large pycnotic figures became rare and fine degeneration granules prevailed. 7. Until the 6th day of incubation the degenerating and/or dead cells were lysed in situ if isolated, or phagocytized by neighbouring mesenchymal cells if present in greater quantities. They could also be expelled to different tissue boundaries. 8. As from the 8th day of incubation, some of the degenerating and dead cells were concentrated around blood vessels. They were also seen in heart cavities and in blood vessel lumina.

Composés d'addition des halogénures de niobium(V) et de tantale(V). V. Stabilité relative des composés des chlorures avec quelques oxydes et sulfures organiques†‡

Abstract: The adducts of niobium(V) and tantalum(V) chlorides with some aliphatic and cyclic oxides and sulfides, studied by NMR. spectroscopy in CHCl3, are found to have 1:1 stoechiometry, at room temperature and lower. In the thioxane complex TaCl5 · C4H8OS two species are present with the ligand coordinated by the sulfur atom or by the oxygen atom, respectively, in a proportion which has been determined. The thioxane adduct of niobium(V) chloride, however, is preferentially coordinated by the sulfur atom. There is also evidence for the species 2MCl5 · C4H8OS. The relative basicity of each donor atom in dioxane, thioxane and dithiane is calculated and discussed. In contrast to the nitrile adducts, whose stability was found earlier to be controlled by inductive factors, the steric factors are more important for the ether and sulfide adducts: MCl5 · Me2X is more stable than the corresponding MCl5 · Et2X (M = Nb, Ta; X = O, S). Both niobium(V) and tantalum(V) chlorides have a soft behaviour, but NbCl5 is a weaker Lewis acid than TaCl5 and shows also a softer behaviour.

The Ring Expansion – Ring Contraction Dichotomy in Aromatic Nitrene and Carbene Reactions I. Arylcarbenes. Preliminary communication

Abstract: 15N-labelling experiments and energy calculations on nitreno-azines and -diazies are in agreement and lead to the theory that both ring contraction and ring expansion in hetarylnitrenes can be one-step processes which are governed mainly by the energy differences between the reacting species and the products.

The tissue dynamics of heart morphogenesis. I. The phenomena of cell death. B. Topography.

Abstract: Zones of cell death in the chick embryo heart were demonstrated by a study of cardiac morphogenesis on the light microscopical level. Between the 2nd and 20th day of incubation 31 foci of cell degeneration were found. The greatest number of dying cells occured on the 4th day of incubation and was located in the heart bulbus and bulbar cushions. The largest number of different degenerative foci were present on the 6th incubation day. Starting on the 10th day of incubation, both the number of degeneration zones and their population of dying cells decreased.

Le système binaire chrome-gallium

Abstract: Resume Le diagramme de phase Cr-Ga a ete etudie sur 60 alliages differents par analyse thermique simple et differentielle, rayons X, microstructure, microsonde de Castaing, dilatometrie et microdurete, sur des echantillons soigneusement recuits. Quatre composes intermetalliques ont ete trouves : Cr3Ga (23 At.-% Ga) subissant une transformation polymorphique a 1100 °C, fond a 1620 °C; CrGa (50 At.-%Ga) existe entre 760 °C et 880 °C; Cr5Ga6(54,6 At.-%Ga) fond a 775 °C; enfin CrGa4 (77At.-% Ga) fond a 700 °C. Tous ces composes a fusion incongruente ont un tres petit domaine d'existence (±0,1 At.-% Ga). La solubilite du gallium dans le chrome solide varie lentement de 12 At.-% a 600 °C jusqu'a 16 At.-% au point de fusion de Cr3Ga. Le point de fusion du gallium est peu affecte par le chrome, avec un abaissement de 0,25 °C seulement.

Hetarylnitrenes V. Reactions of Tetrazolopyrazine Ring Contraction of Nitrenodiazines in Solution. Preliminary communication

Abstract: Thermolysis of tetrazolopyrazine (1) in organic solvents gives pyrazinylnitrene (2) which undergoes ring contraction to 1-cyanoimidazole (3). 7-Methyl-5-methylthio-tetrazolo[1,5-c]pyrimidine (4) likewise gives 1-cyano-2-methylthio-4-methyl-imidazole (6). The two tetrazoles also undergo ring contraction to 1-cyanoimidazoles by gas chromatography, and 1 gives a low yield of 3 by photolysis. Thermolysis of 1 and 4 in cyclohexane gives aminopyrazine (7) and 6-amino-4-methyl-2-methylthio-pyrimidine (8), respectively. Tetrazolo[1,5-a]pyrimidines (9) give only 2-aminopyrimidines (10). 1-Cyanoimidazole, formed by thermolysis of 1 in acetic acid, reacts further to give 1-acetylimidazole, which with more acetic acid gives imidazole and acetic anhydride. An earlier report [2] of ring expansion of pyrazinylnitrene in acetic acid is discredited. In protic deuteriated solvents (D3O, CH3OD), tetrazolopyrazine reacts as an enamine, specifically exchanging HC(6) for deuterium.

The Relationship between C6H5N Isomers. Pyrolysis of isatins

Abstract: The pyrolysis of methyl isatins is described. Examination of the toluidines formed by elimination of 2 CO followed by H-abstraction indicates that 1H-benzazirines (12) are inter-mediates. The interconversion of 1H- and 1aH-benzazirine (15) is not detectable. 1-Phenyl-benzotriazole does not give a benzazirine intermediate.

Composés d'addition des chlorures de terres rares avec le méthanol, l'éthanol et le propanol‐2. Préparations, solubilités et réactions de transsolvatation

Abstract: By reaction of hydrated rare earths chlorides (M = La, Nd, Sm, Gd, Dy, Er, Yb, Y) with orthoformates, the following adducts have been prepared: MCl3· 4MeOH, MCl3 ·3EtOH (M = La, Nd, Sm, Gd, Yb), MCl4 · 4 EtOH (M = Dy, Er, Y); adducts MCl3 · 3iso-PrOH have been prepared by successive action of methyl orthoformate and of 2-propanol. The solubilities of these adducts in the corresponding alcohols at 25° (for the lanthanum adducts equally at 0 and 50°) are given. Two examples of the transsolvatation of these compounds, yielding adducts with weakligands, are described.

Magnetic field effects on the electrical conductivity due to flucíuations of the superconducting order parameter above T c

Abstract: The electrical conductivity above the transition temperatureT c due to fluctuations of the superconducting order parameter has been measured in aluminum films in the presence of a magnetic field (parallel and perpendicular to the film surface), as well as in the absence of a magnetic field. It has been found, in particular from the results in a perpendicular magnetic field, that the Aslamazov-Larkin theory (AL) and its extension can be applied for temperatures close toT c . A deviation from the theoretical linear relation (AL) σn/σ′(T) ∼ ln(T/T c ) in zero and parallel field might be explained in terms of the Maki-Thompson model (MT), which is consistent with previous experiments in Al films. However, the transition width due to fluctuations in a perpendicular magnetic field is not always enhanced, contrary to the prediction of the MT model. Even in the cases in which they are enhanced, the transition width is smaller than the value predicted by the MT model.

Specific heat of type-II superconductors in magnetic fields near T c

Abstract: The GLAG theory predicts that the value of the specific heatC M in the mixed state just below the transition to the normal state, is a function of the Ginzburg—Landau (GL) parameter κ, even for vanishingly small magnetic fields(T≈T c ).C M is thus different from the specific heatC S in the pure superconducting state(H=0) for all κ except κ≅1.9. Experimental results of the authors generally confirm this paradoxical prediction which is not in contradiction with the thermodynamics of phase transitions. To experimentally clarify this behavior close toT c , Nb80Mo20(κ≅4) and Pb98In2(κ≅0.8) specimens are studied in fields much smaller than those usually applied (down to17 Oe). A new method for measuring specific heat in decreasing as well as increasing temperature is introduced. Very good agreement with the theory is found for fields higher than ∼120 Oe while a deviation is observed close toT c for lower fields where values of the Abrikosov lattice parameter would become larger than 1 µ. The sense and the magnitude of the deviation are such thatC M andC S would be equal for fields of 20 Oe and below. Possible explanations are discussed. It is suggested that a fundamental modification of the vortex state structure occurs in small fields close toT c .

Chemische Verschiebungen bei 17O-NMR. und Hydratations geschwindigkeiten von cyclischen Ketonen mit transannularer Wechselwirkung†

Abstract: In 8- and 9-membered cyclic ketones, transannular interactions of an EtN group or an O atom shift considerably the 17O signal of the carbonyl group to higher fields; S appears to have no such effect. The same ketones show markedly diminished speeds of water addition, compared to simple ketones; this reaction was followed by measuring the rate of oxygen exchange between 17O-labelled ketones and (unenriched) water. Transannular interaction inhibits completely in N-ethyl-azacyclodecane-6-one the exchange reaction, including labelling attemps.

Fluxoid Pinning in Superconductors by a Periodic Array of Magnetic Particles

Abstract: We assume a two-dimensional array of ferromagnetic particles on the surface of a thin type-II superconductor in a transverse magnetic field. With a particle at the center of each fluxoid, the pinning forceP and critical current increase ΔJ c due to the particles are calculated. General expressions without arbitrary parameters are given forP and ΔJ c as functions of magnetic field strength and the characteristics of the superconductor and the particles. For broad ranges of conditions values ofP and ΔJ c greater than 10−7 dyn and 105 A/cm2 result and for certain physically realistic sets of conditions,P>10−6 dyn and ΔJ c>106 A/cm2 are predicted. The above effects should be readily observable. An experiment for setting up the assumed conditions is proposed and discussed in some detail.

Transaminase activities of root protoplasts

Abstract: Deux systemes transaminasiques (GOT et GPT) de protoplastes, obtenus mecaniquement et enzymatiquement a partir de cellules de racines d'Allium cepa, sont analyses. Les resultats indiquent que l'activite transaminasique (GOT etant superieur a GPT) des protoplastes est le reflet de celles des cellules a partir desquelles ils ont ete prepares (et ceci notamment en rapport avec leur etat de differentiation). Par ailleurs, les protoplastes formes mecaniquement sont plus actifs; ceci indique notamment que les enzymes employees pour degrader les parois perturbent la biochimie et la physiologie des protoplastes obtenus.

On the Social Behavior in a Stable Group of Long-Tailed Field Mice (Apodemus Sylvaticus). I. an Interpretation of Defensive Postures

Abstract: The social behavior of a group of four adult (2 ♂ ♂ and 2 ♀ ♀) long-tailed field mice (Apodernus sylvaticus) living together for a long period of time in a large terrarium is described and analyzed. As a rule, the social behavior patterns correspond to those described for other rodent species. Analysis of the occurrence of encounters involving defensive postures with other types of encounters, and the behavior of the mice before they display defensive postures suggest that not only attack and flight, but also amicable and non-social tendencies could be involved in the elicitation of this type of behavior.

Renin secretion in the earliest stage of Goldblatt-type hypertension in rats.

Abstract: Unilateral nephrectomy and constriction of the remaining renal artery in the rat induced a sustained increase of systolic blood pressure, which becomes significant as soon as 90 minutes after operation, and a transient rise in renal venous as well as in peripheral plasma renin activity between 20 and 180 minutes after operation. Unilateral nephrectomyper se, after 90 and 180 minutes, caused a significant fall of the systolic blood pressure, a slight increase of renal venous renin activity after 20 and 45 minutes, and between 3 and 24 hours after operation it was followed by a significant decrease of peripheral plasma renin activity. An increased secretion of renin from the “clamped” kidney may thus contribute to the initial rise of blood pressure in rats with Goldblatt-type hypertension.

Esterase polymorphisms in European and American populations of the periwinckle, Littorina littorea (Gastropoda).

Abstract: La structure genetique de 7 populations du gasteropode marinLittorina littorea a ete etudiee par analyse de phenotypes d'esterases reveles par electrophorese sur gel de polyacrylamide. Les populations des USA (Maine, Massachusetts), d'origine recente, ont davantage de variation geographique que celles de France, d'origine ancienne. De plus, parmi ces dernieres il y a reduction de l'heterozygotie dans l'echantillon semi-isole du Golfe du Morbihan.

Kinetics of the current-induced phase transition in type-I superconductors

Abstract: An experimental investigation of the kinetics of the destruction of superconductivity by rectangular current pulses was made on cylindrical Sn and In wires of different purities and diameters. The study was based on the observation of the variation of the voltage along the sample during the transition. As shown by Rothen and Bestgen, only the timet 1 between the beginning of the transition and the onset of the intermediate state can be determined with this method. The results show that if the currentI is sufficiently larger than the critical currentI c (typicallyI⪞1.15I c ), then both shape of the voltage pulses and the transition times agree well with the predictions of the electromagnetic theory of these authors. The transition is, in that case, controlled by the electromagnetic damping associated with the penetration into the normal material of the magnetic field due to the current. IfI is close to c , then the transition is much slower than predicted by the theory and seems to be essentially governed by thermal effects, i.e., absorption of latent heat, generation of Joule heat, and heat exchange with the helium bath; a small influence of superheating is observed in indium samples.

Electron microscopic study of the striated muscle fibers in the pineal body of Wistar rats

Abstract: Unter 35 Pinealdrusen von erwachsenen Wistar-Ratten wurden 8 mit quergestreiften Muskelfasern gefunden. Diese liegen in der Peripherie des Organs und in der Nahe des Pinealstiels. In 3 Fallen wurden direkte Kontakte zwischen Muskelfasern und Kapillaren gesehen.

General and renal toxicity of phenacetin, paracetamol and some anti-mitotic agents in the rat.

Abstract: The general and the renal toxicity of large doses of phenacetin, paracetamol, some antimitotic drugs and other constituents of analgesic mixtures was investigated in medium term toxicity tests in a large number of rats. Phenacetin and paracetamol depressed food intake and retarded growth. 800–1200 mg/kg · day paracetamol induced a larger mortality than 1500–3000 mg/kg · day phenacetin. Both analgesics and isophthalanilide, an antimitotic agent, induced hyperchromic anemia. Phenacetin induced methemoglobinemia more readily than paracetamol. Neither the analgesics, nor caffeine, sodium nitrite, isophthalanilide or mercaptopurine depressed GFR, maximal urinary concentration after dehydration plus vasopressin, urinary dilution after hypotonic expansion, or urinary acidification. Phenacetin, paracetamol and isophthalanilide depressed the fractional excretion of urea by the kidney. Very large doses of paracetamol slightly increased the proteinuria and the urinary excretion of tubular cells. Phenacetin and paracetamol induced degenerative histological alterations in cortical proximal and distal tubules, detected and quantitated under blind conditions. There were no inflammatory changes, nor any medullary or papillary lesions. The degenerative lesions could not be explained by the presence of methemoglobinemia or hemolysis. Isophthalanilide actually “improved” the histological appearance of the kidneys. The urinary excretion of tubular cells was not significantly correlated with the severity of the histological changes. It was concluded that neither phenacetin nor paracetamol exert major nephrotoxic effects in rats.