Showing papers by "University of Lausanne published in 1969"

EARLY STAGES OF INTESTINAL ABSORPTION OF SPECIFIC ANTIBODIES IN THE NEWBORN : An Ultrastructural, Cytochemical, and Immunological Study in the Pig, Rat, and Rabbit

Abstract: In mammals, passive immunity is transferred from mother to offspring by transplacental passage or by intestinal absorption. The rabbit receives antibodies exclusively across the placenta, whereas intestinal absorption is the principal source of antibodies for the new-born pig. In the rat, passive immunity is transferred by both pathways. The role of the jejunal absorptive cells was investigated in these three species, by the use of specific immune globulins as tracers of protein absorption. Rabbit anti-peroxidase and anti-ferritin antibodies were injected into the jejunum of newborn pigs, rats, and rabbits, and absorption was studied over the first 2 hr. The specific antibodies were detected in glutaraldehyde-fixed tissues after in vitro treatment with the antigens, and in sera by immunological methods. Intact antibodies are transferred into the circulation of the pig and the rat, but not into that of the rabbit. In the three species, the jejunal absorptive cells take up antibodies by endocytosis. In the pig, the antibodies are transported across the epithelium in vacuoles. In the rabbit, the endocytosis of antibodies triggers a lysosomal response and all absorbed antibodies are trapped in lysosomes. In the rat, both situations are found; there is no evidence of transfer of antibody fragments into the circulation.

IgA with “Secretory Piece” in Bovine Colostrum and Saliva

Abstract: WE have shown that in bovine colostrum and saliva there is a secretory IgA with a sedimentation, coefficient of 11S and a secretory piece, previously unknown and comparable with the 11S IgA described in human and rabbit external secretions. These secretory IgA contain molecules of 7S IgA with an additional protein segment called the transport or secretory piece1–5. Furthermore, the free form of the secretory piece is identified in bovine colostrum and also in mature milk which contains very little IgA.

Photochemische Umwandlungen. 30. Mitteilung [1]. Zur Kinetik der Norbornadien‐Quadricyclan‐Photocycloaddition

Abstract: Quantum yields for several norbornadiene quadricyclane conversions have been determined under various experimental conditions (Tab. 1). The data are interpreted in terms of a singlet intermediate of type 15.

Effects of sodium deficiency, potassium deficiency and uremia upon the steroidogenic response of rat adrenal tissue to serotonin, potassium ions and adrenocorticotropin.

Abstract: Quartered adrenal glands of rats kept on a sodium-deficient diet or uremic after bilateral nephrectomy were found to produce more aldosterone and less deoxycorticosterone in vitro than adrenal tissue of normal rats. On the other hand, dietary potassium deficiency led to a decreased aldosterone production and an increased deoxycorticosterone production. These differences in corticosteroid production became especially marked when the adrenals were stimulated in vitro by serotonin, adrenocorticotropin (ACTH) or a high potassium concentration in the incubation medium. In adrenals of sodium-deficient or uremic rats aldosterone production was stimulated to the same extent by the addition of progesterone, deoxycorticosterone or corticosterone, whereas in normal adrenal tissue aldosterone production was highest when corticosterone was added to the incubation medium. Only added corticosterone significantly stimulated aldosterone production in adrenals of potassium-deficient rats. These results indicate that the st...

Photochemische Umwandlungen. XXVII [1]. Ein «stabiles» Benzoloxid Vorläufige Mitteilung†

Abstract: By thermal isomerization of the 3-oxa-6.7-diphenyl-tetracyclo [3.2.0.02, 7. 04, 6]-heptane-1. 5-dicarbomethoxylate (4) besides the oxanorbornadiene 3 and the hydroxy-fulvene 7, the ‘stable’ benzeneoxide 7-oxa-2.5-diphenyl-bicyclo [4.1.0] hepta-2.4-diene-3.4-dicarbomethoxylate (5) has been isolated. In the temperature range −50 to 170°C no equilibration with the monocyclic oxepine 6 has been detected.

Superconvergent sum rules for pion--pion scattering.

Abstract: Sum rules for pion-pion scattering amplitudes are derived using analyticity, crossing symmetry and rigorous or ad hoc asymptotic bounds. They are superconvergent in the sense that they involve only integrals over physical quantities. They differ from the simplest superconvergent relations because absorptive parts as well as derivatives of absorptive parts with respect to the momentum transfer appear in the integrals. The fact that one of the sum rules is likely to be violated provides an experimental evidence for the necessity of subtractions. Our present information on pion-pion scattering (known resonances and high-energy behaviour as predicted by the Regge-pole model) is in qualitative agreement with the sum rules. They are used for setting the orders of magnitude of Borne pion-pion parameters.

Human chorionic somato-mammotropine (HCSM): lipolytic action of a pure preparation on isolated fat cells.

Abstract: The lipolytic activity of Human Chorionic Somato-Mammotropine (HCSM) (5 - 50 - 100 μg./ml.) on the release of glycerol and FFA in the isolated epididymal fat cells of the rat is described. At the same time, the lipolytic activity of different concentrations of HGH (5.0–50.0 μg./ml.) and of 2,5-5 – 12,5–25 mμg./ml. ACTH as standard of cellular reactivity was tested. All the experiments were carried out both in the presence and absence of 10 mμg./ml. of dexamethasone. The results demonstrate that the lipolytic action of HCSM does not require the presence of dexamethasone and is quite different from the lipolytic action of HGH. HCSM used by the authors showed a lipolytic action at a level of 5 μg./ml., which increased with the concentration of the hormone. The release of FFA did not appear to be correlated with that of glycerol and suggests an increase in cellular reesterification capacity.

L'hydrolyse acide des diazocétones alcoylées: Formation d'ions α-acylcarbonium secondaires

Abstract: Hydrolysis of secondary diazoketones CH3COCN2R (R Me, Et, isopropyl) by aqueous perchloric acid is characterized by rate-determining protonation demonstrated by solvent isotope effects kD2O/kH2O = 0,4–0,6 and by the intervention of general acid catalysis. The product determining step, yielding keto-alcohols and keto-olefines, is independent of added nucleophiles; this is interpreted as resulting from the intermediate formation of (more or less free) αhyphen;ketocarbonium is ions. The hydride shift observed wih III (R = isopropyl) supports this interpretation. The difference between hydrolysis of primary and of secondary diazoketones is discussed.

Renin, Angiotensin, Aldosterone

Abstract: We studied the morphology of the juxtaglomerular apparatus on wedge excisions of the kidney, obtained in the course of operations, on 3 patients with primary hyperaldosteronism, using light as well as electron microscopy.

Effets diabétogènes des diurétiques thiazidiques et du solvant N -monométhylamide de l'acide acétique chez le rat

Abstract: Aucun effet diabetogene ni hyperglycemiant aigu de l'hydrochlorothiazide (HCT) n'a ete decele par des determinations de la glycemie a jeun (avant et 2–8 h apres l'administration d'HCT) et de la tolerance au glucose effectuees chez des rats normaux et des rats sensibilises a un effet diabetogene par une pancreatectomie subtotale ou par l'injection d'une dose subdiabetogene d'alloxane, au cours d'un traitement de 6 semaines par des doses de 50–200 mg/kg · jour d'HCT p. o. — De fortes doses (plus de 3 ml/kg) de N-monomethylamide de l'acide acetique (NMMAA), solvant qui fut utilise dans la preparation d'une solution injectable commerciale d'hydrochlorothiazide, ont par contre exerce des effets diabetogenes tres marques chez le rat. Toute dose lethale de NMMAA a induit chez cet animal un syndrome diabetique, c'est-a-dire une hyperglycemie progressive avec aeido-cetose metabolique, ressemblant au syndrome diabetique aigu induit par l'injection d'une forte dose de serum anti-insulinique. — Des fractions de doses lethales administrees quotidiennement pendant plusieurs jours ont exerce des effets diabetogenes et lethaux cumulatifs: la substance ou l'un de ses metabolites toxiques apparait persister longtemps dans l'organisme du rat.-Des doses sublethales de NMMAA ont induit une hyperglycemie reversible d'une duree de quelques jours. Nous avons donc constate que le diabete produit par le NMMAA etait soit transitoire soit lethal. Aucun signe de toxicite ne s'est manifeste au cours d'un traitement de 6–8 mois par des doses inferieures a 0,5 ml/kg · jour. — Chez les rats intoxiques par une dose lethale de NMMAA, une correlation positive tres significative a ete notee entre les valeurs seriques d'insuline immuno-reactive (IRI) et les valeurs de glycemie. Bien qu'ils aient ete, a glycemie comparable, superieurs a ceux constates dans le serum de rats normaux apres surcharge de glucose, les taux d'IRI se trouvant dans le serum des rats intoxiques n'ont pas ete en mesure de s'opposer a l'elevation reguliere de la glycemie jusqu'a la mort. — L'effet hypoglycemiant d'insuline cristalline porcine est apparu inhibe chez les rats intoxiques par le NMMAA, compare a l'effet observe chez des rats normaux ou en diabete alloxanique.-Utilisant l'augmentation de l'oxydation du premier atome de carbone du glucose-l-C14 par le tissu adipeux epididymaire du rat, in vitro, comme index metabolique de l'activite insulino ide du serum (ILA), nous n'avons pas constate, dans le serum des rats intoxiques et en etat de forte hyperglycemie, des taux d'ILA significativement superieurs a ceux presents dans le serum de rats temoins a jeun. Alors que, chez des rats normaux, la fraction de l'ILA serique supprimable par serum anti-insulinique (SILA) s'elevait fortement, comme l'IRI, au cours de l'hyperglycemie induite par une surcharge de glucose, cette fraction SILA n'est pas apparue en quantites decelables dans le serum des animaux intoxiques. L'IRI serique de ces animaux n'a donc semble-t-il pas exerce d'effet «insulin-like» sur le tissu adipeux isole de rat normal.-Les faits observes amenent a la conclusion que les rats intoxiques par le NMMAA inactivent et l'insuline endogene et l'insuline exogene. Bien qu'ayant perdu son activite metabolique, l'insuline endogene inactivee reste immunologiquement competente.

Calicen Hochpolare Dicyan‐diphenyl‐derivate [1] [2]. Vorläufige Mitteilung

Abstract: Three dicyano-diphenyl-calicenes have been synthesized. Judged by the dipole moments, the uv. and nmr. data, there is appreciable charge separation in the ground states.

Effect of Preganglionic Stimulation Upon RNA Synthesis in the Isolated Sympathetic Ganglion of the Rat

Abstract: Publisher Summary This chapter discusses the influence of the preganglionic stimulation on the RNA metabolism of the sympathetic cervical ganglion of the rat The preganglionic stimulation is followed by an increased synthesis of RNA mainly during the postactivation period The increase in RNA synthesis can take place during the activation, but it is enhanced strongly at the end of the activation and lasts several hours The increased synthesis is not influenced by the blockade of the muscarinic junctions responsible for the slow synaptic potentials On the other hand, the blockade of the nicotinic junctions, leading to the disappearance of the action potential, prevents the stimulation of RNA synthesis It is impossible to decide if the lack of enhanced synthesis is because of the absence of transmitter action on the synaptic membrane or because of the lack of depolarization of neurons

Presynaptic spike and excitatory postsynaptic potential in sympathetic ganglion: their modifications by pharmacological agents.

Abstract: Publisher Summary An action potential derived from the activity of presynaptic nerve endings can be recorded from the sympathetic ganglion of the rat. The purpose of this work is to demonstrate the precise relationship of this presynaptic spike with the excitatory postsynaptic potential (EPSP). The synaptic efficiency can be affected in three ways: (1) modifications of the quantity of the transmitter available, (2) modifications of the amount of the transmitter released by presynaptic nerve impulse, and (3) changes in the postsynaptic response to the transmitter. Calcium ions are a cofactor for the release of the transmitter, but after preganglionic stimulation, they also affect the quantity of the transmitter available later. The peculiar sensitivity of presynaptic endings is related to their huge surface-to-volume ratio and their high metabolic needs depending on an external energy supply. The early facilitation after activity and the effect of cesium chloride potentiate the transmission by increasing the size of presynaptic spikes.

Changes in ultrastructure and synaptic transmission in the sympathetic ganglion during various metabolic conditions.

Abstract: Publisher Summary This chapter presents a study on the electrophysiological response and ultrastructure of the superior cervical ganglion. The presence of O 2 allows the tissue to use internal substrates, such as glycogen, lipids, or amino acids. The neurons maintain their functional and morphological properties. In the absence of O 2 , the tissue has to cover all its metabolic requirements through anaerobic glycolysis. In a high O 2 pressure condition, the function is lost much later but irreversibly. An increase in the amount of glucose in the solution prolongs the time when transmission is possible. In this condition, there appear to be both a lesion of the neurons and one of the presynaptic fibers. The chapter describes the correlation among the irreversible loss of synaptic transmission, metabolic events, and the ultrastructural changes in three well-defined conditions: lack of glucose in the incubation medium, lack of O 2 in the presence of glucose, and O 2 under pressure.

A propos des ≪chloride cells≫ dans l'épithélium des lamelles branchiales du poisson rouge

Abstract: L'ultrastructure des lamelles branchiales et specialement celle des ≪chloride cells≫ du poisson rouge (Carassius aureus) a ete etudiee. Nous avons constate que du materiel amorphe floconneux, faiblement adielectronique etait attache aux endroits des ≪creux apicaux≫. Afin de preciser la nature de ce materiel, nous avons etudie ces structures au microscope electronique avec les techniques suivantes: acide periodique methenamine d'argent, colorations au fer colloidal et au bleu d'alcian. Apres la reaction a l'acide periodique methenamine d'argent, de fines precipitations aux endroits des ≪creux apicaux≫, correspondant au materiel floconneux visible apres la fixation au glutaraldehyde tetroxyde d'osmium, etaient visibles. La coloration au bleu d'alcian revelait des particules fortement colorees formant un film plus ou moins continu a la surface libre des lamelles, sauf aux endroits oo les ≪chloride cells≫ sont en contact avec la surface. La et notamment dans les 2creux apicaux≫, du materiel legerement granuleux, de faible densite, faisait une couche assez epaisse attachee a la membrane cellulaire. Tenant compte des resultats d'autres auteurs et de nos propres observations, nous considerons que la plus grande partie du materiel se trouvant a la surface des ≪chloride cells≫, et particulierement dans les ≪creux apicaux≫, est de type glycoproteique.

Experimental depigmentation of guinea pig skin by selective toxic action of the monoethyl ether of hydroquinone on melanocytes

Abstract: Hydrochinon-monoathylather ist eine beim schwarzen Meerschweinchen besonders wirksame depigmentierende Substanz. Ihre Wirkung auf die Melanocyten wurde elektronenoptisch untersucht. Es ergibt sich daraus, das die Melanocyten schon im Verlaufe einer 3–6 tagigen Behandlung selektiv geschadigt werden und schlieslich ganz aus der Epidermis verschwinden. Gewisse Befunde deuten darauf hin, das die geschadigten Melanocyten entweder in Auflosung ubergehen oder durch in die Epidermis eingewanderte Makrophagen phagocytiert werden, wobei sich die Makrophagen nach der Phagocytose wieder ins Corium zuruckziehen und so den Zellkadaver aus der Epidermis entfernen.

Groupes de départ inhabituels lors de cyclisations dans la série des quinoxalines, II [1]†

Abstract: Quinoxaline-3-ketones substituted by different groups in position 2 (I) are easily cyclized by hydroxylamine and phenylhydrazine to form isoxazolo[4, 5-b] quinoxalines (II) and pyrazolo [3, 4-b] quinoxalines (III) respectively. The reactions proceed via the oximes resp. phenylhydrazones. Groups displaced are not only the customary leaving groups of aromatic SN2 reactions (halogens, OH), but likewise H, COOH, CONH2, CO-Ar, and, less easily, benzyl groups; methyl and phenyl groups were not displaced. The displacement of hydride ion in the presence of excess of hydroxylamine resp. phenylhydrazine is explained in terms of an extension of the theory of osazone formation.

Study of the metabolism in vitro of glucose in the rat epididymal fat tissue. Stimulating effect of palmitic acid.

Abstract: The rat epididymal fat tissue was incubated with glucose differently labelled with 14C, and the effect of palmitate bound to albumin was studied in the absence or presence of insulin. No inhibition by palmitate of the glucose metabolism was observed. On the contrary, it was demonstrated that palmitate stimulates the different pathways of the glucose metabolism, particularly the fatty acid neosynthesis. The results are discussed in relation to the glucose and palmitate metabolism in the adipose cell, and in relation to the role in vivo of the adipose tissue in the decrease of the glucose assimilation observed in conditions which abnormally increase the serum level of free fatty acids.