Regulation of Prostaglandin E2 (PGe2) and PGF2a Production by oxytocin and Interferon-t in Bovine endometrial cell lines

Chez les ruminants, la prostaglandine lutéolytique F₂α (PGF₂α) est produite dans l'endomètre par les cellules endometriales épithéliales en réponse à l'oxytocine (OT). Par ailleurs, la prostaglandine potentiellement lutéoprotective et pro-nidation PGE₂ est stimulée dans les cellules stromales de l'endomètre en réponse au signal d'origine embryonnaire interféron-t (IFNt). Afin de pousser plus loin les études in vitro amorcées avec des cultures primaires, nous avons établi des lignées stables de cellules endométriales de l'endomètre bovin. Les cellules épithéliales (bEEL) et stromales caronculaires (CSC) ont servi à l'étude de la signalisation et de la régulation transcriptionnelle responsable de la production des prostaglandines (PGs). Des études phénotypiques et fonctionnelles ont révélé qu'autant les cellules bEEL que les CSC ont retenu les caractéristiques distinctives des cultures primaires. Les cellules bEEL s'avèrent "un modèle antilutéolique in vitro" typique car l'IFNt y inhibe la production de PGF₂α. induite par l'OT en 3-6 h. De plus, l'effet inhibiteur de l'IFNt n'est pas médié par la diminution du récepteur à l'oxytocine ou l'expression de la cycloxygénase-2 (COX2) tel que stipulé chez le mouton. Les résultats suggèrent plutôt que l'IFNt peut interférer dans l'axe de signalisation de la production de PGF₂α induite par l'OT. De ce fait, nous avons étudié le mécanisme de transduction du signal de PGF₂α induit par l'OT dans les cellules bEEL. Le relâchement de PGF₂α induit par l'OT est dépendant de l'activation de Ras par la régulation extracellulaire du signal du module kinase V% (ERK 1/2). La transactivation d'EGFR, ainsi que l'activation de c-Src et PI3K sont requis pour l'activation de RAS. En résumé, les résultats suggèrent que la sous-unité activé Gαiβy serait impliquée dans la production de PGF₂α induite par l'OT. À l'instar de ce qui a été observé in vivo, l'IFNt à concentration élevée stimule préférentiellement la production de PGE₂ dans les cellules CSC alors qu'il induit COX2 de manière concentration-dépendante dans les deux types de cellules bEEL et CSC. Il est donc tentant de spéculer que la reconnaissance maternelle de la grossesse chez les ruminants est un phénomène physiologique transitoire d'inflammation régulé par l'effet paracrine de l'IFNt induisant le PGE₂ stromal

Organomercury, -rhodium and -palladium intermediates in organic synthesis

Chapter I describes the synthesis of arylolefins in fair to good yield by the cross-coupling reaction of arylmercurials and vinyl halides catalyzed by 10% ClRh(PPh(,3))(,3). The reaction appears to involve initial oxidative addition of the vinyl halide to the rhodium(I) catalyst to yield a vinyl rhodium(III) species and subsequent arylation by the organomercurial to generate an aryl vinyl rhodium(III) intermediate which reductively eliminates the olefin and regenerates the catalyst;Chapter II details an improved, stereospecific synthesis of vinylmercurials from alkynes using catecholborane, followed by mercuric acetate plus sodium acetate. A vinylmercurial useful in prostaglandin synthesis is prepared using this procedure;Chapter III summarizes our efforts towards the total synthesis of brefeldin-A using the reaction of a vinylpalladium species with cyclopenetene derivatives as a first key step. Even though the reactions lead to the expected product(s), the yields could not be optimized. An alternative approach using the reaction of a vinylcuprate with cyclopentadiene monoepoxide also leads to the expected key intermediate, but the yield again could not be optimized;In Chapter IV, new synthetic methodology is developed for the synthesis of an ethano-bridged prostaglandin endoperoxide analogue using the selective ozonolysis of a double bond in the presence of an acetylenic bond as a key step. The second part of Chapter IV details our unsuccessful efforts to synthesize an etheno-bridged prostaglandin endoperoxide analogue by the reaction of soft carbanions with nonbornadiene-palladium dichloride

Dopunska prehrana ribljim uljem poboljšala je funkciju jajnika, koncepciju i određene reprodukcijske pokazatelje kod kobila pasmine marvari

We investigated the effect of dietary fish oil supplementation on the development of the ovarian follicles, corpus luteum (CL), conceptus and certain reproductive events in Marwari mares, since it is reported to improve reproduction in cows. Accordingly, non-lactating mares (n = 20) were randomly assigned into two groups (10 per group) and fed either the control diet (CTR) or a diet enriched with fish oil (FOS) to supplement n-3 polyunsaturated fatty acids (PUFA) at the rate of 64 mg/kg body weight/day for 70 days or until 45 days post-ovulation in the mares that became pregnant. Estrus was detected using a teaser and insemination was performed using frozen thawed semen in the experimental mares. Development of the ovarian follicle, CL and conceptus were recorded using trans-rectal ultrasonography. Plasma concentrations of progesterone and estradiol were estimated by radioimmunoassay. In the FOS group, the diameter of the largest follicle from day 4 of estrus until ovulation, and the diameter of the CL on day 7 post-ovulation (D7PO) were greater (P<0.05). However, on day 15 post-ovulation (D15PO), the CL diameter increased significantly in the pregnant mares. Dietary fish oil significantly improved the development of the embryo as evidenced by an increase in the diameter of the embryonic vesicle on day 15 post-ovulation (D15PO), and the embryo proper on day 28 post ovulation (D28PO). Further, the mean plasma estradiol concentration was higher on the day of estrus onset (P<0.05) and day 4 of estrus (P<0.01) in the FOS group. Similarly, dietary fish oil significantly increased the plasma progesterone on D15PO in the pregnant mares (P<0.01). Although the duration of estrus was shorter by 19 hours (P<0.05), the length of the estrous cycle did not vary in the FOS group. A non-significant increase in the pregnancy rate was observed in the mares that received fish oil. It was concluded that dietary fish oil supplementation improved ovarian function and embryonic development in the Marwari mares.Na temelju prethodnih izvješća o poboljšanju reprodukcije krava, kod kobila pasmine marvari istražili smo učinak ribljeg ulja kao prehrambenog dodatka na razvoj folikula jajnika, žutog tijela, koncepcije i određenih reprodukcijskih pokazatelja. U skladu s ciljem, 20 kobila koje nisu bile u laktaciji je metodom slučajnog izbora podijeljeno u dvije skupine s po 10 kobila. Za razliku od kontrolne skupine, kobile u eksperimentalnoj skupini hranjene su obrokom obogaćenim ribljim uljem u obliku dodatka koji je sadržavao n-3 polinezasićene masne kiseline (PUFA), u dnevnoj količini od 64 mg na jedan kg tjelesne mase. Eksperiment je trajao 70 dana, odnosno za kobile koje su ostale gravidne do 45 dana nakon ovulacije. Estrus je praćen teaserom, a osjemenjivanje je provedeno zamrznutim sjemenom. Razvoj folikula jajnika i žutih tijela te gravidnosti praćeni su transrektalnim ultrazvukom. Koncentracija progesterona i estradiola u plazmi procijenjena je radioimunološkom metodom. U eksperimentalnoj skupini utvrđen je veći (P<0,05) promjer najvećeg folikula od 4. dana estrusa do ovulacije i veći promjer žutog tijela 7. dan nakon ovulacije. No, 15. dan nakon ovulacije promjer žutih tijela bio je signifikantno povećan kod gravidnih kobila. Obrok obogaćen ribljim uljem signifikantno je poboljšao razvoj embrija, što se očitovalo povećanjem promjera embrionalne vezikule 15. dan nakon ovulacije i povećanjem embrija 28. dan nakon ovulacije. Nadalje, u eksperimentalnoj skupini kobila srednja koncentracija estradiola u plazmi bila je veća na dan početka estrusa (P<0,05) i 4. dan estrusa (P<0,01). Slično tome, obrok obogaćen ribljim uljem kod gravidnih je kobila signifikantno (P<0,01) povećao progesteron u plazmi 15. dan nakon ovulacije. U kobila eksperimentalne skupine je, uz varijacije estrusnog ciklusa, utvrđeno i za 19 sati kraće trajanje estrusa (P<0,05). Povećana stopa gravidnosti kod kobila dohranjivanih ribljim uljem nije bila signifikantna. Zaključeno je da je hranidba s dodatkom ribljeg ulja kod kobila pasmine marvari poboljšala funkciju jajnika i razvoj embrija

Scintillation Counters for the D0 Muon Upgrade

We present the results of an upgrade to the D0 muon system. Scintillating counters have been added to the existing central D0 muon system to provide rejection for cosmic ray muons and out-of-time background, and to provide additional fast timing information for muons in an upgraded Tevatron. Performance and results from the 1994-1996 Tevatron run are presented.Comment: 30 pages, 25 postscript figure

Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV

We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.Comment: 11 pages, 2 figures, 2 table

Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

Search For Heavy Pointlike Dirac Monopoles

We have searched for central production of a pair of photons with high transverse energies in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV using $70 pb^{-1}$ of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of $610, 870, or 1580 GeV/c^2$ on the mass of a spin 0, 1/2, or 1 Dirac monopole.Comment: 12 pages, 4 figure

The Dijet Mass Spectrum and a Search for Quark Compositeness in bar{p}p Collisions at sqrt{s} = 1.8 TeV

Using the DZero detector at the 1.8 TeV pbarp Fermilab Tevatron collider, we have measured the inclusive dijet mass spectrum in the central pseudorapidity region |eta_jet| < 1.0 for dijet masses greater than 200 Gev/c^2. We have also measured the ratio of spectra sigma(|eta_jet| < 0.5)/sigma(0.5 < |eta_jet| < 1.0). The order alpha_s^3 QCD predictions are in good agreement with the data and we rule out models of quark compositeness with a contact interaction scale < 2.4 TeV at the 95% confidence level.Comment: 11 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

Search for High Mass Photon Pairs in p-pbar --> gamma-gamma-jet-jet Events at sqrt(s)=1.8 TeV

A search has been carried out for events in the channel p-barp --> gamma gamma jet jet. Such a signature can characterize the production of a non-standard Higgs boson together with a W or Z boson. We refer to this non-standard Higgs, having standard model couplings to vector bosons but no coupling to fermions, as a "bosonic Higgs." With the requirement of two high transverse energy photons and two jets, the diphoton mass (m(gamma gamma)) distribution is consistent with expected background. A 90(95)% C.L. upper limit on the cross section as a function of mass is calculated, ranging from 0.60(0.80) pb for m(gamma gamma) = 65 GeV/c^2 to 0.26(0.34) pb for m(gamma gamma) = 150 GeV/c^2, corresponding to a 95% C.L. lower limit on the mass of a bosonic Higgs of 78.5 GeV/c^2.Comment: 9 pages, 3 figures. Replacement has new H->gamma gamma branching ratios and corresponding new mass limit