Showing papers by "University of Lausanne published in 1984"

VIP and noradrenaline act synergistically to increase cyclic AMP in cerebral cortex

Abstract: There is growing evidence that two, or possibly more, neurotransmitters can coexist within the same neurone. In particular, the presence of a peptide and a biogenic amine has been demonstrated in the same terminals of central and peripheral neurones. These findings have led to the hypothesis that neurotransmitters, coexisting within the same neurones, can interact at pre- or postsynaptic sites in a functionally coordinated manner. However, interactions between neurotransmitters contained in distinct neuronal systems terminating within the same region of the central nervous system (CNS) can be envisaged. We have examined this last possibility in the cerebral cortex, an area of the CNS where the two neurotransmitters vasoactive intestinal polypeptide and noradrenaline are contained in separate neuronal systems and where they both stimulate the formation of cyclic AMP. We report here that vasoactive intestinal polypeptide and noradrenaline act synergistically to stimulate the formation of cyclic AMP and that this synergistic interaction is antagonized by the specific alpha-adrenergic antagonist phentolamine.

Water‐Exchange Mechanism of Tetraaquapalladium(II). A Variable‐Pressure and Variable‐Temperature Oxygen‐17 NMR Study

Abstract: Water exchange of square-planar Pd(H2O)42+ has been studied as a function of temperature (240 to 345 K) and pressure (0.1 to 260 MPa, at 324 K) by measuring the 17/O-FT-NMR line-widths of the resonance from coordinated water at 27.11 and 48.78 MHz. The following exchange parameters were obtained: k298ex = (560 ± 40) s−1, ΔH* = (49.5 ± 1.9) kJ mol−1, ΔS* = – (26 ± 6) J K−1 mol−1 and ΔV* = – (2.2 ± 0.2) cm3 mol−1. The values refer to an aqueous perchlorate medium with an ionic strength between 2.0 and 2.6 m and a perchloric acid concentration between 0.8 and 1.7 m, and are interpreted in terms of an associative (a) activation for the exchange. The exchange rate for Pd(H2O)42+ is 1.4 × 106 times faster than for Pt(H2O)42+ at 298 K. A comparison with reactions between other nucleophiles and Pd(H2O)42+ is also made.

Hepatic hemobilia: hemorrhage from the intrahepatic biliary tract, a review.

Abstract: Hepatic hemobilia is defined as hemorrhage arising from pathological changes in the intrahepatic biliary tract. The main causes are iatrogenic trauma, cholangitis, tumors, and coagulopathy. The salient features of the hemobilia syndrome are described and their causes explained. The treatment, when necessitated by hemorrhage or clot formation, is either resection of the liver or occlusion of the responsible artery by ligature or embolization. The iatrogenic trauma may be operative, resulting from instrumental lesion of the bile ducts, needle biopsy, transhepatic cholangiography, biliary tract prosthesis, or inlaying hepatic artery catheters. Among the inflammatory etiologies, special attention is given to nematodes in the ducts, “the tropical hemobilia.” Spontaneous hemobilia may, just as nose bleeds or hematuria, result from treatment with anticoagulants.

Characterization of plasminogen activators from normal human breast and colon and from breast and colon carcinomas.

Abstract: Triton X-100 and NaSCN extracts of 18 normal breast and colon tissues and of 20 breast and colon carcinomas were fractionated by SDS-PAGE and plasminogen activators (PA) revealed by a zymographic method. Four different lysis bands, corresponding to MWs of 54,000, 68,000, 95,000 and 110,000 were observed. Using immunoadsorption with specific antisera against urokinase (UK) and tissue PA (t-PA), we found that all normal tissue extracts contained free t-PA (68 kd). Some of these revealed, in addition, a complex (110 kd) of t-PA with a 40-kd component. The latter presumably represents the fast-acting specific inhibitor of t-PA and UK. Most carcinoma extracts contained, in addition to the two t-PA-related lysis bands, the UK-related 54 kd PA, and some a 95 kd complex of UK with the 40 kd component. For each extractant, mean total fibrinolytic activity of normal and tumor tissue was comparable when measured on conventional fibrin plates, but breast and colon carcinomas contained higher concentrations of UK-related PA. PA activity was higher in normal and carcinoma NaSCN extracts than in the corresponding Triton X-100 extracts. In general, Triton X-100 but not NaSCN extracts of malignant tissue contained a high concentration of fibrinolytic inhibitors. Mixing experiments revealed that the inhibitory activity was mainly directed against UK. It was abolished by acidification of the carcinoma extracts. The anti-UK inhibitory activity was absent in extracts of normal breast or colon and appears to be different from the 40 kd fast-acting PA inhibitor. These studies show that malignant transformation of breast and colon is accompanied by important changes of the production of a UK-related PA and of an inhibitory activity directed against UK.

Study on lipid metabolism in obesity diabetes

Abstract: Knowing the relationship between obesity and diabetes, the purpose of our work was to study the alterations in lipid metabolism as measured by continuous indirect calorimetry in the course of a 100-g oral glucose-tolerance test in groups of obese patients without and with diabetes, respectively. Seventy-nine obese patients participated in the study. They were divided into four groups according to the degree of carbohydrate intolerance: group A, normal glucose tolerance; group B, impaired glucose tolerance; group C, diabetes with hyperinsulinemic response to the load; group D, diabetes with impaired insulin response. All four groups of patients presented an increase in lipid oxidation, both in the fasting state and during the three-hour glucose tolerance test, when compared to the control group. The lipid oxidation rate was roughly parallel to plasma free fatty acid (FFA) levels. The contribution of lipids to energy expenditure was higher in obese as compared to control subjects. These observations suggest that the larger part taken by lipids in the energy metabolism of both nondiabetic and diabetic obese humans is a consequence of their increased fat stores and that the resulting decrease in carbohydrate metabolism may lead, as a late consequence, to alterations in glucose tolerance. The latter may result in delayed glucose storage and oxidation in the obese patient.

Optical resolution of 7-oxabicyclo[2.2.1]hept-21-ene derivatives. Diastereoselectivity in the formation of cyanohydrine-brucine complexes

Abstract: Note: Univ lausanne,inst chim organ,ch-1005 lausanne,switzerland Reference LGSA-ARTICLE-1984-009doi:101002/hlca19840670629 Record created on 2005-11-09, modified on 2017-05-12

Immunohistological study of malignant diffuse mesotheliomas of the pleura

Abstract: Paraffin sections from fifteen cases of malignant diffuse mesothelioma of the pleura and five cases of bronchial adenocarcinoma infiltrating the pleura were examined with an antiserum specific for factor VIII related antigen and with antisera against various epithelial markers: keratin, carcinoembryonic antigen (CEA), fat globule membrane antigen and secretory component. In all adenocarcinomas all the epithelial markers were present whereas the factor VIII related antigen was absent. The distribution of the fat globule membrane antigens, keratin, secretory component and factor. VIII related antigen varied from one mesothelioma to another. The mesotheliomas were generally negative for CEA. The three mesotheliomas which were positive for CEA were also positive for alcian blue after hyaluronidase treatment. Amongst the markers used, CEA seems the most useful for the differential diagnosis between carcinoma and mesothelioma. However, the simultaneous detection of several markers allows the characterization of various phenotypes. Some of them are close to the phenotypes of true adenocarcinoma. A relation between a given phenotype and the biological behaviour of the tumour has still to be demonstrated.

Impulse conduction regulates myelin basic protein phosphorylation in rat optic nerve.

Abstract: The influence of action potential conduction in myelinated axons on the state of phosphorylation of myelin basic protein was studied in rat optic nerve incubated in vitro. For this purpose we used a technique that permits continuous recording of the responses of nerves to electrical stimulation together with the "back-phosphorylation" assay. Our results indicate that action potential conduction, but not electrical stimulation, increased the state of phosphorylation of myelin basic protein. The increment in basic protein phosphorylation was related to the number of impulses conducted, up to a maximal change which occurred after 12 X 10(3) impulses. Also, the effect of action potential conduction was reversible, since the state of myelin basic protein phosphorylation returned to control levels within 5 min of stopping stimulation. These findings raise the interesting possibility that myelin basic protein phosphorylation plays a role in some dynamic function of myelin, perhaps related to ion transport or to the process of recovery of ionic gradients.

Mapping of the genes coding for the two major vaccinia virus core polypeptides.

Abstract: We have mapped the genes coding for two major structural polypeptides of the vaccinia virus core by hybrid selection and transcriptional mapping. First, RNA was selected by hybridization to restriction fragments of the vaccinia virus genome, translated in vitro and the products were immunoprecipitated with antibodies against the two polypeptides. This approach allowed us to map the genes to the left hand end of the largest Hind III restriction fragment of 50 kilobase pairs. Second, transcriptional mapping of this region of the genome revealed the presence of the two expected RNAs. Both RNAs are transcribed from the leftward reading strand and the 5'-ends of the genes are separated by about 7.5 kilobase pairs of DNA. Thus, two genes encoding structural polypeptides with a similar location in the vaccinia virus particle are clustered at approximately 105 kilobase pairs from the left hand end of the 180 kilobase pair vaccinia virus genome.

New Saponins from Phytolacca dodecandra l'HERIT

Abstract: Three bidesmosidic saponins (1–3) have been isolated from the methanolic extract of the berries of Phytolacca dodecandra l'HERIT (Phytolaccaceae) by a combination of rotation locular counter-current chromatography and column chromatography on reversed phase (RP-8) With MeOH/H2O. The structures have been established by 1H-NMR, 13C-NMR, FAB-MS, and D/CI-MS, as well as on the basis of acidic and basic hydrolyses. The monodesmosidic saponins 1a–3a obtained after partial hydrolysis with a base exhibit strong molluscicidal activity against the schistosomiasis-transmitting snail Biomphalaria glabrata. Saponins 1–3, 1a, and 3a are reported for the first time, whereas 2a has been identified previously in the aqueous extract of P. dodecandra berries.

Solid‐state polymerization of butadienes. Crystal structure and solution properties of a stereoregular amphoteric 1,4‐trans‐polybutadiene

Abstract: The double salt 1 consisting of the hydrochloride of 6-amino-2,4-trans-hexadienoic acid and cadmium chloride in a 2:1 stoichiometry polymerizes in the crystalline state if exposed to UV or γ irradiation. A stereoregular polymeric ampholyte is formed in an extended chain macroconformation, embedded in an inorganic matrix. The crystal structure of the polymerized crystals and the solution properties of the polymer are reported. Polymerized crystals are triclinic, space group P1, a = 7.2144 A, b = 7.2447 A, c = 18.5936 A, α = 104.49°, β = 96.631°, γ = 95.706°, Z = 2. The structure consists of 2-dimensional layers of polymer and inorganic CdCl6 octahedra alternatively stacked in the third dimension. The cadmium ions can be separated from the polymer by a precipitation as insoluble CdS. After separation from the inorganic material the polymer is soluble in strong acids and bases and insoluble in neutral water. From viscosity measurements of alkaline solutions of the polymer, an average molar mass of 4 × 104 g/mol can be deduced. The polymer selectively adsorbs divalent transition metal ions if suspended in an aqueous solution of transition metal salts. The structure of the resulting polymer–metal complexes is discussed.

Variation in pattern of mystacial vibrissae in mice A quantitative study of ICR stock and several inbred strains

Abstract: We report on the variation in the pattern of mystacial vibrissae in ICR mice, of which one-half of the about 600 animals investigated showed one or more supernumerary whiskers (SWs). The SWs and their follicles--in all respects identical to the units of the standard pattern except for their smaller size--occurred at a restricted number of sites. In addition, a limited number of mice from two BALB/c strains were analyzed. Half of them also had one or more SWs, but mainly at one site. Mice of the C3H/HeJ and DBA/2J(a) strains were virtually without SWs, whereas animals from the NMRI strain were standard without exception. Nearly all animals of the C57BL/6J strain lacked between 1 and 4 vibrissae, always from one or two of the same adjacent sites. There was a slight overall predominance for the left side of the face to bear SWs and there was no clear-cut association with sex; the entire population was without obvious defects. The sites where extra or lacking whiskers occur are associated with the lines of fusion between the medial and the lateral nasal fold, and between the latter and the maxillary arch. Where tested, we always found a topologic equivalency between the pattern of the whisker follicles and the contralateral pattern of the "barrels"--multineuronal units in layer IV of the parietal cerebral cortex--whether the pattern was standard, "enriched," or lacking in elements. The data presented in this paper provided a basis for several studies carried out subsequently on animals that are the offspring of those characterized here, studies suggesting that the occurrence of supernumerary and of lacking whiskers has a genetic basis.

Inhibition of antigen-induced T-cell clone proliferation by antigen-specific antibodies.

Abstract: Attempts to inhibit the recognition of soluble antigens by T lymphocytes using antibodies specific for the antigen in question have been uniformally unsuccessful, in contrast to the observed specific inhibition of antibody generation by B cells. One exception is the unique situation whereby anti-hapten antisera inhibit the T-cell proliferative responses observed when hapten-specific T lymphocytes or clones are cultured with hapten-derivatized cells or proteins. The inability to inhibit T-cell functions by antigen-specific antibodies has been interpreted in several ways: (1) T cells possess a different repertoire from B cells; (2) the antibodies tested recognize epitopes present on the native antigen, whereas T cells recognize non-native (processed) structures; (3) the antigenic determinant(s) recognized by T cells on the surface of antigen presenting cells are either not accessible to antibodies, or are present in low amounts. The development of antigen-specific T-cell clones and monoclonal antibodies both specific for the same antigenic determinants now allows this question to be investigated definitively. Here, we report for the first time the specific inhibition of antigen-induced T-cell clone proliferation by a monoclonal antibody directed against the relevant soluble protein antigen.

Fonction de Möbius d'un groupe fini et anneau de Burnside

Abstract: Keywords: lattice of subgroups ; idempotents ; Burnside ring ; Mobius function ; Crapo's formula ; soluble groups ; principal series Reference CTG-ARTICLE-1984-001doi:10.1007/BF02566359 Record created on 2008-12-16, modified on 2017-05-12

Cyclodopa glucoside ( = (2S)-5-(β-D-glocopyranosyloxy)-6-hydroxyindoline-2-carboxylic acid) and its occurrence in red beet (beta vulgaris var. rubra L.)

Abstract: Cyclodopa glucoside ( = (2S)-5-(β-D-glucopyranosyloxy)-6-hydroxyindoline-2-carboxylicacid; 1a) is prepared from betainin (2a) via a base exchange reaction. Its purification and physical properties are described. The compound is N-formylated in dilute HCOOH solution. Cyclodopa glucoside is contained in considerable amount in redbeet juice varying from 0.07 to 1.9 mmol/kg or from 12 to 46% relative to teh content of betanin. Teh occurrence of free cyclodopa glucoside supports its role as intermediate in betanin biosynthesis.

Thyroid hormones and thermogenesis: The metabolic cost of food and exercise

Abstract: To mimic plasma T3 levels observed in a previous overfeeding study, six lean healthy men received replacement amounts of L-thyroxine (200 μg/d) to block endogenous thyroid hormone production while consuming their habitual diet. After 4 weeks equilibration on T4, L-triiodothyronine (T3) was given (45 μg/d) in addition to T4, to produce mild T3-thyrotoxicosis, for another 2 weeks. At the end of this period T3 was discontinued but the subjects continued to receive T4 for another 2 weeks. Resting metabolic rate, exercise efficiency, and the thermic effect of food were measured using a ventilated hood, open circuit indirect calorimeter at the end of each phase of the experiment. There was a significant increase in the resting metabolic rate of 6% (P<0.01) while the subjects were mildly T3-thyrotoxic. The increase in energy expenditure however, during exercise on a bicycle ergometer or following a 500 kcal liquid-formula meal remained unaltered in the same situation. Thus, mild T3-toxicosis does not alter the efficiency of exercise or the thermic effect of food. These results suggest that the increased plasma T3 levels, observed in overfeeding, could explain corresponding increases in resting metabolic rate but not changes in the efficiency of exercise or the utilization of food.

Applications of Rotation Locular Countercurrent Chromatography in Natural Products Isolation

Abstract: Purification of natural products and the fractionation of crude plant extracts are processes which traditionally involve adsorption and/or molecular exclusion chromatography. While countercurrent chromatography avoids the irreversible adsorption and decomposition frequently encountered in adsorption chromatography, the classical countercurrent distribution technique is both time- and solvent-consuming, consequently it is of limited value today. Rotation locular countercurrent chromatography (RLCC) is one of three new countercurrent techniques, the others being droplet contercurrent chromatography (DCCC)1 and planet coil countercurrent chromatography (PCCCC)2, which have revived the chromatographic application of liquid-liquid partition. We have employed a commercially available RLCC apparatus in the isolation of several natural products with a broad range of polarity demonstrating the versatility of the RLCC with regard to the functionality of the compounds to be isolated.

Genetic drift and selection: Their respective weights in the morphological and genetic differentiation of four species of shrews in Southern Europe (Insectivora, Soricidae)

Abstract: Summary On the basis of 26 mandibular measurements performed of 272 individuals from 52 localities, inter-specific morphological variance (23.8 % of the total variance) and morphological distances were computed by a discriminant analysis between four species of shrews, Sorex araneus, S. coronatus, S. granaries and S. samniticus, which are parapatric in Southern Europe. These distances show a low correlation (r = 0.330) with the genetic distances evaluated by electrophoretic studies. Multiple regression analyses showed that 26.3 % of the total morphological variance of these shrews can be explained by the geoclimatic conditions they meet in their environment, and allowed to remove this selective effect by using the residues of these regressions. The remaining interspecific variance is distributed randomly on the principal components computed on these residues, and thus it has to be admitted that the selection has not another influence on the registered morphological variation. This remaining interspecific variance is only 2.9 % of the total morphological variance, which leads to conclude that 20.9/23.8 = 87.8 % of the interspecific variance are mere consequences of the parapatric distribution of these shrews. The morphological distances computed on the residual, which are independent of selection, are clearly correlated to the genetic distances (r = 0.922). The ecological and evolutionary entanglements of these results are discussed. Resume Derive genetique et selection: Leur importance respective dans la differentiation morphologique et genetique de quatre especes de musaraignes dans le sud de l'Europe (Insectivora, Soricidae) Une analyse discriminante fondee sur 26 mesures mandibulaires a permis de calculer la variance inter-specifique (23.8 % de la variance totale) et les distances morphologiques entre 4 especes de musaraignes, Sorex araneus, S. coronatus, S. granarius et S. samniticus, qui sont parapatriques dans le sud de l'Europe. Ces distances sont pauvrement correlees aux distances genetiques obtenues par analyse electrophoretique (r = 0.330). Des regressions multiples ont d'une part permis d'attribuer 26.3% de la variance morphologique enregistree aux conditions geoclimatiques auxquelles sont soumises ces musaraignes, et d'autrepart d'obtenir, avec les residus, des variables independantes de cette selection. La variance inter-specifique residuelle est distribuee au hasard sur les composantes principales calculees sur ces residus, et l'on peut donc admettre qu'elle n'est pas due a un autre effet de la selection. Elle ne represente plus que 2.9 % de la variance totale du systeme, ce qui amene a conclure que 20.9/23.8 = 87.8 % de la variance interspecifique enregistree sont une simple consequence de la distribution parapatrique de ces 4 especes. Les distances morphologiques calculees sur les residus, et donc independantes de la selection, sont clairement correlees avec les distances genetiques (r = 0.922). Les implications ecologiques et phylogeniques de ces resultats sont discutees. Zusammenfassung Genetische Drift and Selektion: ihr jeweiliger Anteil an der morphologischen und genetischen Differenzierung bei vier Spitzmausarten in Sudeuropa (Insectivora, Soricidae) Bei vier parapatrischen sudeuropaischen Spitzmausarten, Sorex araneus, S. coronatus, S. granaries und S. samniticus, wurden mittels 26 Unterkiefermasen (an 272 Spitzmausen von 52 Lokalitaten) die morphologische Varianz (23.8 % der totalen Varianz) und die morphologischen Distanzen durch eine Diskriminanzanalyse berechnet. Die morphologischen Distanzen sind nur schwach mit den durch Elektrophoresestudien ermittelten genetischen Distanzen korreliert (r = 0.330). Multiple Regressions-analysen zeigen, das 26.3% der morphologischen Varianz durch die lokalen geoklimatischen Bedingungen erklart werden kann. Die verbleibende interspezifische Varianz erscheint nach einer Hauptkomponentenanalyse zufallig verteilt, weshalb angenommen werden mus, das die Selektion keinen anderen Einflus auf die festgestellte morphologische Varianz ausubt. Diese verbleibende interspezifische Varianz entspricht nur 2.9 % der totalen Varianz, was zum Schlus fuhrt, das 20.9/23.8 = 87.8 % der interspezifischen Unterschiede allein auf die parapatrische Verbreitung dieser Spitzmause zuruckzufuhren ist. Die aus der residuellen Varianz ermittelten, von der Selektion unabhangigen morphologischen Distanzen sind klar mit den genetischen Distanzen korreliert (r = 0.922). Die okologische und die stammesgeschichtliche Bedeutung dieser Resultate werden diskutiert.