La microvascularisation de la muqueuse vaginale et ses variations au cours du cycle ovarien chez la Femme

Résumé A la suite de recherches antérieures intéressant la vascularisation de la trompe utérine et celle de l'ovaire, la présente étude concerne la microvascularisation de la muqueuse vaginale chez la Femme et se fonde sur l'examen de dix vagins humains prélevés chez des sujets en période d'activité génitale, vagins dont le système vasculaire est injecté à l'encre de Chine gélosée.L'étude de l'angioarchitectonie de la muqueuse vaginale en général laisse apparaître un dispositif vasculaire spécifique de cette dernière et représenté au niveau du chorion par des artérioles superficielles qui s'arborisent en de multiples branches se résolvant en un réseau capillaire sous-muqueux; ce dernier est constitué d'une part, d'un dense réseau capillaire à mailles ovalaires ou polygonales, étalé sous la couche basale de l'épithélium malpighien, d'autre part, d'anses capillaires intra-papillaires, sensiblement perpendiculaires à l'épithélium malpighien et se répétant à intervalles réguliers. Ce réseau capillaire est draîné par un plexus veineux étendu que résument de volumineuses veines au calibre irrégulier.Les variations de cette angioarchitectonie au cours des diverses phases du cycle ovarien sont essentiellement marquées au cours de la 2e phase de ce cycle où elles se caractérisent par une augmentation de calibre des artérioles comme des capillaires et surtout par l'accroissement de la hauteur et de la spiralisation des anses capillaires.

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The angioarchitectony of the submucous network of the human vagina and its variations during the ovarian cycle

Summary The microvascularization of the vaginal mucosa has been investigated on 10 human vaginae taken from autopsies of women having been in their sexual active period, the vascular system of the vaginae being injected with solutions of China ink and gelose.The angioarchitectony of the vaginal mucosa shows a specific vascular pattern. The latter is represented at the level of the stroma by superficial arterioles which divide into multiple branches giving rise to the submucous capillary network. This network consists on one hand of a thick capillary plexus with ovale or polygonal stitches, spread under the basal layer of the malpighian epithelium, and on the other hand of intrapapillary capillary creeks arranged in regular intervals and perpendicularly oriented to the malpighian epithelium. This capillary network is drained by a wide spread venous plexus connected with big veins of irregular calibre.The variations of this angioarchitectony are especially pronounced during the second part of the menstrual period, when the calibre of the arterioles as well as that of the capillaries creeks grow in height and become spiralized.

     

Allelopathy as a factor in ecological process

Zusammenfassung Allelopathie (chemische Hemmung) ist ein Faktor bei ökologischen Prozessen wie Konkurrenz, Dominanz, Sukzession, Produktivität.Es ist zu erwarten daß die von Pflanzen ausgeschiedenen Chemikalien sich in der Umgebung der Pflanze ansammeln, bis sie für andere Pflanzen, oder für ihre eigene Entwicklung, eine hemmende Konzentration erreichen. Auch steht es fest, daß manche Pflanzen sich so gegen Tierfraß schützen.Biochemische Produkte kommen weitgehend in biotischen Wechselwirkungen vor und allelopathische Effekte spielen in fast allen natürlichen oder angepflanzten Pflanzengemeinschaften eine Rolle.

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This study has been supported by National Science Foundation, contracts GB-149, GB-4058, and GB-6814, under which this is the tenth publication.     

Immunocytochemical localization of histones H2B, H3 and H4 in pronuclei and four-cell stages of porcine embryos. Preliminary results

In this preliminary work, using pig embryos ultrastructural immunocytochemistry with polyclonal antibodies against purified histones was used to demonstrate both their localization and the time of their appearance in pronuclei, from 15 h after ovulation (pronuclear stage) to 48 h postinsemination (4-cell stage). In pronuclei, the histones H2B, H3, and H4 were located in the heterochromatin as soon as it appeared. Usually, one of the pronuclei seemed to be more heavily labelled. The chromatin facing the zone of pronuclear contact formed a bowl-shaped region in each pronucleus heavily labelled for these histones. The so-called pseudo-nucleoli were present in both pronuclei and contained H2B. In 4-cell stages, the labelling intensities of heterochromatin for H2B, H3 and H4 were equal in all the nuclei. H2B was still evident in the pseudo-nucleoli, but in a lower quantity than before. The condensed chromatin located either under the nuclear envelope or surrounding the pseudo-nucleoli was heavily labelled for H2B, H3 and H4.     

Supra-additive stimulation of adenylate cyclase activity by prostaglandin E2 andD-Ala2-met-enkephalinamide in the guinea-pig superior cervical ganglion: Role of Mg2+ ions

Agonists modulation of Mg²⁺-dependent adenylate cyclase activity has been studied in guinea-pig superior cervical ganglion crude membrane preparations. In the absence of receptors ligands, Mg²⁺ stimulates the enzyme in a concentration-dependent manner. The dose-activation curve shows heterogeneity and two components with higher and lower apparent affinity states, are extrapolated. In the presence ofD-Ala²-met-enkephalinamide only one component is present and the apparent affinity of the ganglionic adenylate cyclase system for the divalent cation as well as Vmax are inhibited. On the contrary, prostaglandin E₂ increases affinity and Vmax values of the lower and, to a lesser extent, of the higher Km component. When the two drugs are tested in combination, not only the inhibitory effect of the opiate is overcome, but a large increase of the apparent affinities and Vmax values for both components is obtained, suggesting the involvement of the Mg²⁺-regulated subunits of the adenylate cyclase system in the supra-additive stimulation mechanism of the enzyme.     

Functional vasoactive intestinal polypeptide (VIP) receptors in human neuroblastoma subclones that contain VIP precursor mRNA and release VIP-like substances

Three phenotypically distinct subclones (SH-SY-5Y, SH-EP, SH-IN) of the human neuroblastoma cell line SK-N-SH were found to possess vasoactive intestinal polypeptide (VIP) precursor mRNA, release immunoreactive VIP, and express high-affinity VIP receptors coupled to adenylate cyclase. The apparent molecular mass for the receptor polypeptide, as determined by covalent cross-linking of 125I-VIP, was 49 kDa. After 2 days in culture, a concentration of immunoreactive VIP equivalent to the binding affinity of VIP to its receptor was found in the medium in two of these clones (SH-IN and SH-EP). Conditioned medium from SH-IN cells competitively displaced 125I-VIP binding and increased cAMP levels in SH-EP cells, indicating that all of the necessary components for a potential autocrine action of VIP exist in SK-N-SH cells. After numerous cell passages, the SH-EP subclone converted to a distinct phenotype in which VIP precursor mRNA and VIP immunoreactivity in the cell and medium were no longer detectable. In correlation, the VIP receptor number increased, and the EC50 for VIP stimulation of cAMP production shifted to a lower concentration. This points to the possibility that the continuous presence of endogenous VIP in earlier passage SH-EP cells causes a modification in VIP receptor number and cell responsiveness to VIP.     

The effect of poly(ADP-ribosyl)ation on native and H1-depleted chromatin. A role of poly(ADP-ribosyl)ation on core nucleosome structure

The effect of poly(ADP-ribosyl)ation on native and H1-depleted chromatin was analyzed by gel electrophoresis, electron microscopy, and velocity sedimentation. In parallel, the interaction of automodified poly(ADP-ribose) polymerase with native and H1-depleted chromatin was analyzed. In H1-depleted chromatin histone H2B becomes the major poly(ADP-ribose) histone acceptor protein, whereas in native chromatin histone H1 was the major histone acceptor. Poly(ADP-ribosyl)ation of H1-depleted chromatin prevented the recondensation of polynucleosomes reconstituted with exogenous histone H1. This is probably due to the presence of modified poly(ADP-ribose) polymerase and hyper(ADP-ribosyl)ated histone H2B. Indeed, about 40% of the modified enzyme remained associated with H1-depleted chromatin, while less than 1% of the modified enzyme was bound to native chromatin. The influence of poly(ADP-ribosyl)ation on the chromatin conformation was also studied at the level of nucleosome in using monoclonal and polyclonal antibodies specific for individual histones and synthetic peptides of histones. In native chromatin incubated in the presence of Mg2+ there was a drop in the accessibility of histone epitopes to monoclonal and polyclonal antibodies whereas upon poly(ADP-ribosyl)ation their accessibility was found to remain even in the presence of Mg2+. In poly(ADP-ribosyl)ated H1-depleted chromatin an increased accessibility of some histone tails to antibodies was observed.     

Components of relative growth rate and sensitivity to nitrogen availability in annual and perennial species of Bromus

Summary Two grass species, the annual Bromus sterilis and the perennial Bromus erectus, were grown from seeds for 28 days in a hydroponic culture system at 1 and 100 M NO₃ ^- in the nutrient solution. At 100 M NO₃ ^-, the relative growth rate (RGR) of the perennial was 30% lower than that of the annual. This was only the consequence of the higher specific mass of its leaves, since its leaf mass ratio was higher than that of the annual and the unit leaf rates (ULR), calculated on an area basis, were similar for the two species. At 1 M, the RGR of the annual was 50% lower than at 100 M, while that of the perennial was not significantly lower. This was due mainly to a lower ULR for the annual. while for the perennial ULR was the same in both treatments. These differences between the two species were all the more striking in that the differences in total nitrogen concentrations and nitrate reductase activities between the two treatments were very similar for both species. These different responses together with differences in the nitrogen productivity of the two species suggest that the level of nutrient availability may play an important role in the distribution of these Bromus species in natural habitats. Scope: Components of growth and response to nitrate availability in annual and perennial grasses     

Immunoquantification and enzyme kinetics of alpha-L-iduronidase in cultured fibroblasts from normal controls and mucopolysaccharidosis type I patients.

alpha-L-Iduronidase activity is deficient in mucopolysaccharidosis type I (MPS I; Hurler syndrome, Scheie syndrome) patients and results in the disruption of the sequential degradation of the glycosaminoglycans dermatan sulfate and heparan sulfate. A monoclonal antibody-based immunoquantification assay has been developed for alpha-L-iduronidase, which enables the detection of at least 16 pg alpha-L-iduronidase protein. Cultured human skin fibroblasts from 12 normal controls contained 17-54 ng alpha-L-iduronidase protein/mg extracted cell protein. Fibroblasts from 23 MPS I patients were assayed for alpha-L-iduronidase protein content. Fibroblast extracts from one MPS I patient contained at least six times the level of alpha-L-iduronidase protein for normal controls--but contained no associated enzyme activity--and is proposed to represent a mutation affecting the active site of the enzyme. Fibroblast extracts from 11 MPS I patients contained 0.05-2.03 ng alpha-L-iduronidase protein/mg extracted cell protein, whereas immunodetectable protein could not be detected in the other 11 patients. Four fibroblast extracts with no immunodetectable alpha-L-iduronidase protein had residual alpha-L-iduronidase activity, suggesting that the mutant alpha-L-iduronidase in cultured cells from these MPS I patients has been modified to mask or remove the epitopes detected by two monoclonal antibodies used in the quantification assay. Both the absence of immunoreactivity in a mild MPS I patient and high protein level in a severe MPS I patient present limitations to the use of immunoquantification analysis as a sole measure of patient phenotype. Enzyme kinetic analysis of alpha-L-iduronidase from MPS I fibroblasts revealed a number of patients with either abnormal substrate binding or catalytic activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cooperative Action of Rhizobium meliloti Nodulation and Infection Mutants during the Process of Forming Mixed Infected Alfalfa Nodules

Alfalfa plants co-inoculated with Rhizobium meliloti nodulation (Nod-) and infection mutants deficient in exopolysaccharide production (Inf-EPS-) formed mixed infected nodules that were capable of fixing atmospheric nitrogen. The formation of infected nodules was dependent on close contact between the inoculation partners. When the partners were separated by a filter, empty Fix- nodules were formed, suggesting that infection thread formation in alfalfa is dependent on signals from the nodulation and infection genes. In mixed infected nodules, both nodulation and infection mutants colonized the plant cells and differentiated into bacteroids. The formation of bacteroids was not dependent on cell-to-cell contact between the mutants. Immunogold/silver staining revealed that the ratio of the two mutants varied considerably in colonized plant cells following mixed inoculation. The introduction of an additional nif/fix mutation into one of the inoculation partners did not abolish nitrogen fixation in mixed infected nodules. The expression of nif D::lacZ fusions additionally demonstrated that mutations in the nodulation and infection genes did not prevent the nif genes from being expressed in the mutant bacteroids.