Showing papers by "Collège de France published in 1969"
192 citations
170 citations
TL;DR: It is impossible to say at present whether the ultrastructural aspect of the nerve studied here is in any way specific, but the abnormalities in the myelin sheaths and the frequency of desmosomes are noteworthy.
Abstract: The principal lesion in this case of chronic early infantile neuropathy is a modification of the Schwann cell resulting in the formation of a concentric network of lamellae formed by a double-layered sheet of basement membrane around numerous, large myelinated and unmyelinated fibers. The abnormalities in the myelin sheaths and the frequency of desmosomes are noteworthy. These peculiarities distinguish this case from other chronic neuropathies described up to now. Nevertheless, it is impossible to say at present whether the ultrastructural aspect of the nerve studied here is in any way specific.
79 citations
TL;DR: Octopine dehydrogenase, an NAD+ enzyme, which catalyzes the dehydrogenation of octopine into arginine plus pyruvale, has been purified from muscles of Pecten maximus and is homogeneous on analytical ultracentrifugation and disc electrophoresis.
71 citations
TL;DR: The results obtained suggested the possibility that the LH molecule was damaged by treatment at acid pH, with an impressive loss of biological activity which could be restored when the dimer was reconstituted.
57 citations
57 citations
TL;DR: In this paper, the B meson is observed in the system (ωπ): its mass, width, and spin-parity are analyzed, and limits are given for the branching ratios B → φπ/B → ωπ and B → KK/B→ππ.
56 citations
TL;DR: Amphetamine and DMI pretreatment in rats enhanced the synthesis of 3 H CA in the two structures examined, and Amphetamine but not DMI induced a similar effect on 3 H-DA newly synthesized and released from striatal slices.
56 citations
TL;DR: The results suggest that a dopaminergic mechanism is involved in LH-release regulation, and that its intervention is only critical during a very short time.
Abstract: In PMS- and HCG-treated immature rats, interruption of catecholamine synthesis by a-methyl-p-tyrosine (α-MT) is only able to block ovulation when treatment is applied between 3:00 and 4:00 PM of the day of proestrus, i.e., during a fraction of the “critical period.” Earlier treatment has only a slight effect upon ovulation intensity. Restoration of brain dopamine (DA) and norepinephrine (NE) levels by administration of their common precursor L-dihydroxyphenylalanine (DOPA) restores ovulation to subnormal levels in α-MT-blocked animals; however, L-threodihydroxyphenylserine(DOPS), which restores NE synthesis only, is ineffective. These results suggest that a dopaminergic mechanism is involved in LH-release regulation, and that its intervention is only critical during a very short time. The effect of αmethyl- DOPA administration, which induces synthesis of the false neurotransmitters α- methyl-DA and a-methyl-NE in catecholaminergic neurons, is in agreement with this hypothesis. Biochemical implications of ...
55 citations
54 citations
TL;DR: Extension de resultats de Eells-Sampson dans le cas riemannien as mentioned in this paper for varietes kAhleriennesM etM sous l'hypotese que la premiere classe de ChernC1(M) soit positive.
Abstract: Extension de resultats de Eells-Sampson dans le cas riemannien. Applications au cas de varietes kAhleriennesM etM’ sous l’hypotese que la premiere classe de ChernC1(M) soit positive.
TL;DR: L'examen autoradiographique des cellules marquees par 125I montre that les proteines iodees ne gagnent pas d'autres structures cellulaires si on prolonge la duree d'incubation, mais on observe une tendance a la dissociation des polysomes.
TL;DR: In this paper, the authors analyzed the three-body annihilation at rest (overline p n \to K\overline K \pi \), from a total sample of 2.22·105 annihilations.
Abstract: We have analysed the three-body annihilations at rest \(\overline p n \to K\overline K \pi \), from a total sample of 2.22·105 annihilations. The annihilation at rest \(\overline p n \to K\overline K \pi \) has been studied by Conforto et al. The « multiple final-state interaction model » developed by them has been used to analyse the Open image in new window annihilation; an overall consistent picture is obtained in this way.
TL;DR: The active thiol group of lombricine kinase from Lumbricus terrestris muscle was labelled with N-ethyl-[1-14C]maleimide as discussed by the authors.
Abstract: The active thiol group of lombricine kinase from Lumbricus terrestris muscle was labelled with N-ethyl-[1-14C]maleimide. The resulting inactivated N-ethyl-[1-14C]succinimido enzyme was then subjected to tryptic hydrolysis.
The peptide containing the labelled essential thiol group was isolated and found to contain: Leu-Gly-Tyr-Ile-Thr-[14C]Cys-Pro-Gly-Ser-Asn-Leu-Gly-Thr-Leu-Arg. The amino acid sequence around this thiol group was very similar with that of homologous ATP: guanidine phosphotransferases previously studied, arginine kinase from Homarus vulgaris muscle, creatine kinases from ox brain and ox muscle and from rabbit muscle.
In addition among the other enzymes of this group, lombricine kinase is of special interest since it is the only dimeric enzyme of molecular weight ≃ 80000 which possesses only one essential thiol group and one nucleotide binding site per two subunits.
TL;DR: In this article, an irreducible representation of a finite-dimensional Lie algebra containing the Poincare Lie algebra and giving rise to isolated positive masses is given, and the representation is poincare partially integrable (which assures the continuous physical spectrum for the energy- momentum vector) and poINCARE-covariant in a weak sense.
Abstract: An example is given of an irreducible representation of a finite-dimensional Lie algebra containing the Poincare Lie algebra and giving rise to isolated positive masses. In addition the representation is Poincare partially integrable (which assures the continuous physical spectrum for the energy- momentum vector) and “Poincare-covariant” in a weak sense.
TL;DR: The physical procedures involved in the intracisternal injection have been tested and shown not to affect the intensity of PS rebound and the effects of recording conditions during paradoxical sleep deprivation in water tanks have been studied.
TL;DR: In this paper, an exact integral equation which can be put in a form generalizing that given by Gell-Mann and Low is presented, showing that a dependence of the bare charge α0 on the observed one α is consistent with the renormalization group.
Abstract: By a precise elucidation of the axioms from which renormalization « groups » result we construct the most general «groups » which include mass renormalization. We discuss in detail the particular case involving only photon field and electron mass renormalizations. An exact integral equation which can be put in a form generalizing that given by Gell-Mann and Low. allows us to show that a dependence of the bare charge α0 on the observed one α is, contrary to an often quoted paradox, consistent with the renormalization group. We demonstrate that in the cases when, the bare or the observed mass of the electron is null or infinite, which should correspond to determined values of α the formal perturbation expansion in α0 of the photon vacuum polarization tensor is no more divergent than a single power of a logarithm. We finally determine wherein lies the failure of the argument leading to the paradox stated above and discuss its implication.
TL;DR: In this article, the presence of anhydrase carbonique exclusivement dans la region du labyrinthe carotidien contenant les cellules chemoreceptrices.
Abstract: On a essaye de localiser histochimiquement l'anhydrase carbonique dans les chemorecepteurs arteriels des Mammiferes, des Batraciens et des Poissons. On a utilise la modification apportee par Hansson a la technique de Haussler.
1.
Chez le Lapin, l'anhydrase carbonique est localisee au niveau des lobules de cellules chemoreceptrices du glomus carotidien.
2.
Chez la Grenouille, on a montre la presence d'anhydrase carbonique exclusivement dans la region du labyrinthe carotidien contenant les cellules chemoreceptrices. Il n'a pas ete possible de determiner le type des cellules dans lesquelles se produit la reaction.
3.
On a pu montrer la localisation intracellulaire de l'anhydrase carbonique dans les cellules pseudobranchiales des Teleosteens. Cette derniere localisation suggere fortement que l'activite enzymatique est liee au systeme de tubules qui s'ouvrent au pole vasculaire des cellules.
TL;DR: In this paper, the D, E and f' mesons were observed in pp annihilations at 0.7 GeV/c and the quantum numbers of the D and E were analyzed.
TL;DR: In this article, a technique nouvelle is presentee permettant l'enregistrement graphique des mouvements de mastication and de deglutition chez le sujet humain.
TL;DR: Ovine luteinizing hormone, as well as cyclic 3′,5′-adenosine monophosphate, stimulates in vitro the biosynthesis of progesterone in the corpus luteum of pseudo-pregnant rats, indicating that cyclic AMP could mediate the action of LH.
TL;DR: In this article, evidence from the K K decay mode for the splitting of the A 2 meson is presented, and the A 1 meson can be split in the K 2 decay mode.
TL;DR: In this paper, it was shown that the four-body pp annihilations at rest cannot be interpreted without the introduction of a Kππ resonance, the C-meson.
TL;DR: ATP:l-arginine phosphotransferase has been isolated from Sipunculus nudus muscle; the preparation is homogeneous to analytical centrifugation, molecular sieving on Sephadex G-100 and electrophoresis on cellogel and on polyacrylamide discs.
Abstract: ATP:l-arginine phosphotransferase has been isolated from Sipunculus nudus muscle; the preparation is homogeneous to analytical centrifugation, molecular sieving on Sephadex G-100 and electrophoresis on cellogel and on polyacrylamide discs.
Treated by 8 M urea, arginine phosphokinase from Sipunculus is dissociated into two subunits having the same molecular weight whereas arginine kinase from lobster gives no dissociation evidence. Furthermore the number of peptides shown on fingerprints of the tryptic hydrolysate of the first enzyme amounts to half of its lysine plus arginine residues. The enzyme from Sipunculus is named arginine kinase type II, to be distinguished from that of molecular weight near 40 000 (arginine kinase type I) and from that of molecular weight 160 000 (arginine kinase type III).
Unlike arginine kinase type I which contains 6 total SH groups and a single reactive and essential SH, arginine kinase type II is found to have 12 total thiols and 6 SH groups reacting at the same rate with 5,5′-dithio-bis-(2-nitrobenzoic) acid or with N-ethylmaleimide. From the numerous thiols similarly exposed results the particular autooxydisability and lability of the enzyme on study. No evidence is shown of the content of the disulfide bridges.
Like arginine kinase type I, arginine kinase type II is strictly specific. The kinetics of the reaction are the same for both: no cooperative effect is observed between guanidine and nucleotide substrates fixation on the enzymes.
TL;DR: In this paper, a Legendre polynomial analysis of the s -channel does not require more than a G-wave and a good description is obtained by extrapolating t -channel Regge pole calculations to these low energies.
TL;DR: In this article, experimental results on the reactions p p p → K 1 O K 2 O π + π − at 0.7 GeV /c were presented on the production of K ∗, S∗, fO, ϕ, ϱ, and the recently proposed F1 meson.
TL;DR: In this article, a double crystal spectrometer is used to obtain a nearly planar incident wave on a thin silicon crystal, and it is shown that the same oscillations should occur in the rocking curves as predicted by the dynamical theory for an incident plane wave.
Abstract: A double crystal spectrometer is used to obtain a nearly planar incident wave on a thin silicon crystal. A theoretical study of the experimental arrangement has been made and it is shown that the same oscillations should occur in the rocking curves as predicted by the dynamical theory for an incident plane wave. The oscillations have been observed using crystals of several thicknesses and several wavelengths. The position of the fringes are in very good agreement with theory and their contrast is quite good.
TL;DR: Ces recherches ont apporte des resultats decisifs concernant les questions du transport des cellules germinales primordiales (CGP) par la voie sanguine and de the colonisation des ebauches gonadiques (EBOs) sur la technique des cultures in vitro.
Abstract: La lignee germinale des Oiseaux fait l9objet, depuis une quinzaine d9annees, de travaux experimentaux bases sur la technique des cultures in vitro . Ces recherches ont apporte des resultats decisifs concernant les questions du transport des cellules germinales primordiales (CGP) par la voie sanguine (technique des parabioses circulatoires in vitro , Wolff & Simon, 1957) et de la colonisation des ebauches gonadiques (technique des associations in vitro , Dubois, 1964, 1968). Recemment, Fargeix (1967 a, b ) utilisant la technique de fissuration du blastoderme de Canard (Wolff & Lutz, 1947) et Dubois (1967 a, b ) ont demontre que les initiales germinales de la blastula sont precocement entrainees par les mouvements morphogenetiques caudo-cephaliques. La migration de l9endophylle vers l9avant les emporte et les distribue dans l9aire extra-embryonnaire du croissant germinal anterieur. Les cellules germinales peuvent y etre identifiees a partir de la 15e h de l9incubation (Reynaud, 1967), avant leur entree dans le mesoblaste.