Showing papers by "Université catholique de Louvain published in 1970"
TL;DR: In this paper, anesthetized fed rats were found to inactivate the liver phosphorylase in the liver of normal rats, but more often was without effect when effective in the diabetic animal.
363 citations
TL;DR: The removal of glucose, AMP and other small molecules from mouse liver extract by filtration through Sephadex G-25 has allowed us to demonstrate that the activation in vitro of glycogen synthetase is much more rapidly attained in the presence of glucose and also when the animals have received prednisolone 3 h before sacrifice.
Abstract: The removal of glucose, AMP and other small molecules from mouse liver extract by filtration through Sephadex G-25 has allowed us to demonstrate that the activation in vitro of glycogen synthetase is much more rapidly attained in the presence of glucose and also when the animals have received prednisolone 3 h before sacrifice. These effects are the result of a shortening of the lag period that precedes the activation of the synthetase; they are conveniently studied in filtrates that have been enriched with sulfate or phosphate ions. Like glucose, caffeine and nicotinamide shorten the lag period and are without action when this period is over; α-particulate glycogen has the opposite effect. No lag period is observed in the presence of AMP, particularly when associated with magnesium acetate. When a liver Sephadex filtrate is incubated in the absence of salts, glycogen synthetase b is converted into a partially active form that is rapidly transformed into synthetase a upon the addition of salt.
These results support the hypothesis that glycogen synthetase phosphatase is initially present in the liver filtrate as a b enzyme, active only in the presence of AMP and magnesium; this b form is converted into its active, a, homologue through the action of a synthetase phosphatase activating enzyme, which is more active after a treatment with glucocorticoids, is stimulated by glucose, caffeine and nicotinamide and inhibited by glycogen, AMP and fluoride.
165 citations
105 citations
TL;DR: The results are compared with values observed in normal subjects and also with those obtained in two control groups: (1) patients with abnormalities of the small intestinal mucosa due to tropical sprue, Whipple's disease, and dermatitis herpetiformis and (2) subjects with normal intestinal mucosity but with low serum levels of either IgA or IgM.
91 citations
TL;DR: In this paper, the slow stages of the catalytic reduction of WO3 to hydrogen tungsten bronzes HxWO3 were studied by NMR spectroscopy between −50 and −195 °C.
80 citations
TL;DR: The effects of several mitochondrial inhibitors on growth and respiration indicate that the requirement of an oxidant for growth is related neither to the functioning of the respiratory electron transport chain nor to the formation of respiratory energy.
Abstract: The respiratory metabolism of Schizosaccharomyces pombe 972h−, a fission, haplontic, “petite negative” yeast, was studied. Glucose and glycerol are good growth substrates and are oxidized under appropriate conditions. l-Lactate, ethanol, malate, and succinate are oxidized but are poor substrates for growth. d-Lactate and pyruvate are neither oxidized nor used for growth. Limited growth was observed under anaerobic conditions. The addition of 0.3% KNO3 to a rich medium relieves the oxygen requirement. A continuous increase of cell respiration during growth on repressive concentration of glucose was observed, suggesting the presence of glucose repression of respiration. Reduced nicotinamide adenine dinucleotide (NADH), succinate, α-glycerophosphate, and ascorbate plus tetramethyl-p-phenylenediamine are oxidized by a mitochondrial fraction. NADH and succinate oxidations are inhibited by antimycin A and NaCN but not by rotenone, suggesting the absence of the phosphorylation site I and the presence of sites II and III. The effects of several mitochondrial inhibitors on growth and respiration indicate that the requirement of an oxidant for growth is related neither to the functioning of the respiratory electron transport chain nor to the formation of respiratory energy. The previously suggested correlations between the nonviability of vegetative “petites” mutants, the absence of repression of respiration by glucose, and the incapacity to grow under anaerobic conditions are thus not strictly valid for S. pombe. Images
78 citations
TL;DR: No viable respiratory-deficient mutants of Schizosaccharomyces pombe 972h(-) could be obtained by acriflavine and ethidium bromide treatments, and results suggest that unstable petites were induced.
Abstract: No viable respiratory-deficient mutants of Schizosaccharomyces pombe 972h − could be obtained by acriflavine and ethidium bromide treatments. These mutagens induce 15 to 70% of microcolonies which, after a growth-lag of a few days, further develop into normal, respiratory-competent colonies. These results suggest that unstable petites were induced. Segregational respiratory-deficient mutants resistant to cobalt sulfate inhibition were isolated. Some of these strains are deficient in cytochrome a + a 3 and respire at low rates. The morphology of their mitochondrial membranes is modified: either the cristae are absent or they show aberrant concentric or tubular structures. Segregational mutants resistant to the respiratory inhibitors, 2,4-dinitrophenol or decamethylene diguanidine, were obtained. Neither mitochondrial structure nor function seems to be modified in these mutants. A segregational mutant resistant to benzimidazole inhibition does not grow on glycerol, although neither growth on glucose nor respiration appear to be affected. Images
58 citations
52 citations
TL;DR: The two main effectors that act antagonistically on the glycogen synthetase and glycogen phosphorylase appear to be glucose and cyclic AMP; thanks to their action, the synthesis of glycogen is inhibited while its degeneration is stimulated and vice versa.
52 citations
TL;DR: In this article, the equilibrium constants of 1:1 and 2:1 stoichiometric complexes have been determined, which are related to the sum of the Hammett σ constants by the following relations: log K1 = 1.73 + 1.30Σσ log K2= 1.57 + 0.05 Σσ+ 0.94 (σ)2 Log K1 is linearly related to Δμ.
51 citations
TL;DR: A three-dimensional reconstitution of glandular volumes and of the endometrium that contains them led to the following conclusion glandularVolume increased by 100 % and stromal volume increased by 50 % in the patients treated with ethinyl-estradiol as compared to the patients treating with mestranol.
TL;DR: The increase in the concentration of cyclic adenosine 3′: 5′-phosphate in the liver after the administration of a small dose of glucagon precedes the inactivation of glycogen synthetase by 1–2 min, in agreement with the role of the nucleotide as second messenger in the hormonal action.
Abstract: The increase in the concentration of cyclic adenosine 3′: 5′-phosphate in the liver after the administration of a small dose of glucagon precedes the inactivation of glycogen synthetase by 1–2 min. This sequence of events is in agreement with the role of the nucleotide as second messenger in the hormonal action. The increase is dose dependent and is the same in control and prednisolone treated mice.
Treatment of mice with glucose or prednisolone causes a slight decrease in the concentration of cyclic adenosine 3′: 5′-phosphate in the liver. The minuteness of this effect is in contrast with the large activation of glycogen synthetase that occurs under the same conditions.
TL;DR: In this article, a linear correlation was established between these two physical variables and from this an enthalpy of fusion for the polycarbonate crystal of 26 Kcal was deduced.
Abstract: Several measurements of the heat of fusion and of specific volume were carried out on bisphenol A-polycarbonate of varying degrees of crystallinity. A linear correlation was established between these two physical variables and from this an enthalpy of fusion for the polycarbonate crystal of 26 Kcal. was deduced.
TL;DR: There is a marked increase in the size and number of lysosome-like cytoplasmic bodies—resembling the condition seen in many storage diseases.
Abstract: Antibodies directed against soluble components from purified liver lysosomes are taken up by fibroblasts and to impair lysosomal function. As a result, lysosomal hydrolases are inhibited, the uptake and digestion of foreign protein are impaired and there is a marked increase in the size and number of lysosome-like cytoplasmic bodies—resembling the condition seen in many storage diseases.
TL;DR: Three different patterns of reaction can be observed which are the counterparts of the three fundamental reactions obtained in Ouchterlony plates.
TL;DR: Goethite, lepidocrocite and hematite were reacted with glycerol and reaction products were studied at various steps of the reaction as discussed by the authors, and after a treatment of 16 hr at 245°C, the final form of a reaction product, a deep green soft solid, was obtained whatever the starting material.
Abstract: Goethite, lepidocrocite and hematite were reacted with glycerol and reaction products were studied at various steps of the reaction. After a treatment of 16 hr at 245°C the final form of the reaction product, a deep green soft solid, was obtained whatever the starting material. According to hydrolysis and chemical analysis, the reaction product can be identified as iron alkoxide. Hydrolysis of the solid by boiling water yielded glycerol and a strongly magnetic material characterized by a spinel structure like maghemite and magnetite.
TL;DR: In this article, the existence of an inversion layer near the metallurgical junction of abrupt asymmetrical /b p/b n/ junctions is examined by means of a simple model, valid for reverse bias.
Abstract: The existence of an inversion layer near the metallurgical junction of abrupt asymmetrical /b p/-/b n/ junctions is examined by means of a simple model, valid for reverse bias. Its influence on the electric field, the potential and the capacitance of the junctions is determined and discussed.
TL;DR: In this article, a Mossbauer investigation in FeAl alloys ranging from 20 to 28 at% Al has been performed, in which a very slight mean electric quadrupole interaction has been measured, which may be due to some directional order, while in the ordered spectra two ordered phases were observed for a composition around 25 at% al.
Abstract: A Mossbauer investigation in FeAl alloys ranging from 20 to 28 at% Al has been performed. In the disordered spectra, which were computer analyzed, a very slight mean electric quadrupole interaction has been measured, which may be due to some directional order, while in the ordered spectra two ordered phases were observed for a composition around 25 at% Al: the DO3-type of ordered structure, in which each Al atom has eight Fe nearest neighbours and six Fe next-nearest neighbours, and another phase with a structure similar to Cu3Au, in which each Al atom has 12 Fe nearest neighbours and six Al next-nearest neighbours. Both phases are ferromagnetic. In the Cu3Au-type structure a strong electric quadrupole interaction has been measured, which is the same as in the Fe3AlC compound. The quadrupole effect does not appear in the DO3-type structure probably because of special relationships between the easy axis of magnetization and the electric field gradient tensor. Measurements of quadrupole effects show that Al should be strongly ionized when alloyed with Fe. This gives a clue to understand the physical reasons why order-disorder transitions appear in such alloys. Below the transition temperature, each Al gets better surrounded exclusively by Fe atoms in order to minimize the Coulomb interaction energy with its neighbours.
In FeAl -Legierungen mit 20 bis 28 at% Al wurde eine Mosbaueruntersuchung durchgefuhrt. In den Fehlerordnungsspektren, die maschinell analysiert wurden, wird eine sehr leichte, mittlere, elektrische Quadrupolwechselwirkung gemessen, die durch eine Richtungsordnung hervorgerufen sein kann, wahrend in den Ordnungsspektren zwei geordnete Phasen fur eine Zusammensetzung um 25 at% Al beobachtet wurden: der DO3-Typ der geordneten Struktur, in dem jedes Al-Atom acht nachste Fe-Nachbarn und sechs ubernachste Fe-Nachbarn besitzt, und eine andere Phase mit einer ahnlichen Struktur wie Cu3Au, in der jedes Al-Atom 12 nachste Fe-Nachbarn und sechs ubernachste Al-Nachbarn hat. Beide Phasen sind ferromagnetisch. In der Struktur vom Cu3Au-Typ wurde eine starke elektrische Quadrupolwechselwirkung gemessen, die dieselbe wie in den Fe3Al-Verbindungen ist. Der Quadrupoleffekt tritt nicht in der DO3-Struktur auf, wahrscheinlich wegen der speziellen Beziehungen zwischen der leichten Magnetisierungsachse und dem Tensor des elektrischen Feldgradienten. Messungen des Quadrupoleffekts zeigen, das Al in der Legierung mit Fe stark ionisiert sein sollte. Dies ergibt einen Anhaltspunkt, die physikalischen Grunde zu verstehen, warum Ordnungs-Fehlordnungsubergange in solchen Legierungen auftreten. Unterhalb der Ubergangstemperatur wird jedes Al-Atom immer besser ausschlieslich von Fe-Atomen umgeben, um die Coulombwechselwirkungsenergie mit seinen Nachbarn zu minimalisieren.
TL;DR: Substantial evidence that Australia antigen is associated with acute and chronic hepatitis, and with hepatitis carriers is found, and the antigen may in fact be the virus itself or some factor very closely connected with it.
TL;DR: Soil moisture had a great influence on the extent of the zone over which the products diffused vertically, as shown by fungicidal and phytotoxic action at various depths in soil columns.
Abstract: Laboratory experiments were carried out to test the effect of two levels of soil moisture and two temperatures on the effectivity and persistence of five soil fumigants. Soil moisture had a great influence on the extent of the zone over which the products diffused vertically, as shown by fungicidal and phytotoxic action at various depths in soil columns. In moist soil spread of the gases from the point of application is much poorer than in dry soils. There was little or no temperature effect in the dryer soil, while in the wet soil diffusion was better at 25° than at 10°C. In studying persistence, as measured by assaying inhibition of germination and growth ofLepidium sativum, it appeared that the tested fumigants can be divided into two groups. In the case of chloropicrin and telone persistence is primarily enhanced by high soil moisture content, and in the case of the fumigants having methyl isothiocyanate as the active principle, by a low soil temperature. With chloropicrin and telone, there is a temperature effect only in the moist soil. Persistence of methylisothiocyanate is only slightly affected by soil moisture. In laboratoriumproeven werd de invloed van temperatuur en vochtgehalte van de bodem op de effectiviteit en persistentie van vijf grondontsmettingsmiddelen onderzocht. De bodemvochtigheid heeft een grote invloed op de verspreiding der produkten, zoals bleek bij de toetsing van fungicide en phytotoxische effecten op verschillende diepten in grondkolommen. In vochtige grond met een laag porienvolume is de verspreiding vanaf het injectiepunt bij deze gasvormige middelen veel geringer dan in droge grond. In vochtige grond was de ontsmette zone groter bij 25°C dan bij 10°C, terwijl in droge grond geen of weinig effect van de temperatuur werd geconstateerd. Bij de bepaling van de persistentie, gemeten als kiem-en groeiremmend effect opLepidium sativum, bleek de getoetste serie middelen in twee groepen uiteen te vallen. De persistentie wordt in het geval van chloorpicrine en telone vooral verlengd door een hoog vochtgehalte, en bij de drie andere, waarvan methylisothiocyanaat het actieve bestanddeel of principe is, door een lage temperatuur. Bij chloorpicrine en telone is er alleen een temperatuureffect in de vochtige grond, terwijl de persistentie van methylisothiocyanaat zeer weinig beinvloed wordt door het vochtgehalte.
TL;DR: A 2½-hr glucose infusion preceded by the rapid injection of a priming glucose load was given to normal subjects, obese subjects and latent diabetics, where the insulin reponse was in the low-normal range while the blood sugar values remained high.
Abstract: A 2½-hr glucose infusion preceded by the rapid injection of a priming glucose load was given to normal subjects, obese subjects and latent diabetics. The insulin response was diphasic with an early transitory peak and thereafter a gradual and higher increase throughout the infusion. In the normal subjects, this response varied in magnitude but it always had an efficient blood sugar lowering effect. In the obese subjects, it was excessive in the early and more especially the latter parts of the infusion but it did not provoke a decrease of the blood sugar. In the latent diabetics, the insulin reponse was in the low-normal range while the blood sugar values remained high.
TL;DR: In this paper, le rendements de tous les produits formes varient avec la dose absorbee par l'hydrocarbure irradie. And les rendements correspondants ne sont mesurables qu'a partir d'une dose de 10 Mrads pour laquelle on trouve une valeur de 0,02 molecule par 100 eV.
01 Jan 1970
TL;DR: In this article, a non-isothermal finite linear theory of viscoelasticity with infinitesimal deformation is presented for "thermo-rheologically simple" solids.
Abstract: Starting with the results for a non-isothermal finite linear theory of viscoelasticity, a systematic derivation of a linearized theory with infinitesimal deformation is presented for ‘thermo-rheologically simple’ solids. A comparison of the resulting constitutive equations and the internal dissipation with those given previously is included.
TL;DR: The magneto-Seebeck effect in bismuth is measured along a bisectrix direction y with the magnetic field rotating in the xz -plane as mentioned in this paper, and the asymmetry due to the "Umkehreffekt" is related to the sense of the binary axis.
TL;DR: Four series of experiments were performed on Tinca tinca, using a simple instrumental technique, in which the fish could regulate its own activity and rest periods as a function of its light tolerance, and results show a great variability between individuals.
Abstract: Four series of experiments were performed on Tinca tinca, using a simple instrumental technique, in which the fish could regulate its own activity and rest periods as a function of its light tolera...
TL;DR: In this article, a serie de derives du diphenyl-1,2 cyano-1 cyclopropane, nous avons etudie l'influence de la substitution sur la frequence de vibration caracteristique du groupe nitrile, sur le spectre electronique and sur le deplacement chimique des protons cycloprepaniques, en resonance magnetique nucleaire.
TL;DR: In this article, the authors presented evidence of N-protonation of the amide group in the case of 2,4-dinitro formanilide, showing that the NO2 groups in the molecule enhance the relative basicity of the nitrogen atom in such a way that the amount of Nprotonated amide can be detected.
Abstract: En etudiant par RMN cinq anilides de formule generale
en milieu acide, les auteurs ont mis en evidence la protonation de l'atome d'azote de l'ion amidonium forme.
Five substituted anilides of general formula
were studied in acidic media (H2SO4MeOH and HSO3ClMe2CO). The unsolved problem of the protonation site (O-protonation and N-protonation) is discussed in terms of the observed NMR shifts [(δNH) and δ(COH)] taking into account several factors including hydrogen bonding and solvent effects.
New dramatic evidence is presented of N-protonation of the amide group; in the case of 2,4-dinitro formanilide, the NO2 groups in the molecule enhance the relative basicity of the nitrogen atom in such a way that the amount of N-protonated amide can be detected.
N-protonation is a function of the acidity, showing a maximum in the region of 40 to 50%.