Browsing by Author "Ortiz, ME"

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    An estradiol metabolite accelerates ovum transport in cyclic rats through non-genomic pathways
    (W B SAUNDERS CO LTD, 2006) Ambriz, GD; Parada Bustamante, A; Orihuela, PA; Ortiz, ME; Villalon, MJ; Croxatto, HB
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    Basic aspects of oviduct function
    (PARTHENON PUBLISHING GROUP LTD, 1997) Croxatto, HB; Ortiz, ME; Villalon, M; Cardenas, H; Imarai, M; Hermoso, M; Velasquez, L; Orihuela, P; Coutifaris, C; Mastroianni, L
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    Muc1 and glycan expression in the oviduct and endometrium of a new world monkey, Cebus apella
    (OXFORD UNIV PRESS INC, 2001) Jones, CJP; Ortiz, ME; Croxatto, HB; Manzur, A; Slevin, G; Aplin, JD
    Cebus apella is a New World monkey that has a menstrual cycle of 18-23 days with implantation at approximately luteal Day 5, The aim of this study was to characterize by lectin- and antibody-labeling the distribution of Mud and associated glycans on the endometrial and oviductal epithelium during the luteal phase of the cycle, Endometrial histology showed a thin endometrium, with glands extending deeply into the myometrium, No obvious evidence of secretory differentiation in cells of either the superficial or the basal segments of glands could be obtained using a panel of antibodies and lectins that marked epithelial glycoprotein, and glycosylation changes observed in some other primate endometrial cycles were not observed in this study, Antibodies to human MUC1 were shown to cross-react with C, apella, and Mud was localized to the apical epithelial surfaces of both the endometrial and the tubal epithelium, with stronger expression in the latter. Again, no cyclic changes were noted, Antibodies specific to the isoform Muc1/Sec showed strong staining at the apical tubal epithelium, but no reactivity was detectable in the luminal epithelium of the uterus. This observation suggests differences between the two glycocalyces and could help to explain why C, apella embryos do not implant in this location.
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    Nitric oxide synthase inhibitors accelerate eCG transport in the rat oviduct by enhancing oviductal smooth muscle activity.
    (SOC STUDY REPRODUCTION, 1999) Villalon, M; Martinez, S; Viggiano, M; Franchi, AM; Herrero, MB; Ortiz, ME; Gimeno, M
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    Post-coital administration of levonorgestrel does not interfere with post-fertilization events in the new-world monkey Cebus apella
    (2004) Ortiz, ME; Ortiz, RE; Fuentes, MA; Parraguez, VH; Croxatto, HB
    BACKGROUND: Experimental evidence to disprove the belief that emergency contraception with levonorgestrel (LNG) prevents pregnancy by interfering with post-fertilization events is lacking. Here we determined the effect of post-coital and pre-ovulatory administration of LNG on fertility and ovulation, respectively, in the Cebus monkey. METHODS: To determine the effect on fertility, LNG 0.75 mg or vehicle were administered orally or s.c. once or twice within the first 24 h after mating occurring very close to the time of ovulation. Females that became pregnant were aborted with mifepristone and re-entered the study after a resting cycle until each of 12 females had contributed, in a randomized order, two LNG and two vehicle-treated cycles. To determine the effect on ovulation, LNG 0.75 mg or vehicle were injected twice coinciding with follicles smaller or larger than 5 mm in diameter. Six females contributed five treated cycles each. RESULTS: The pregnancy rate was identical in vehicle- and LNG-treated cycles. LNG inhibited or delayed ovulation only when treatment coincided with a follicle <5 mm diameter. CONCLUSION: In Cebus monkeys, LNG can inhibit or delay ovulation but, once fertilization has taken place, it cannot prevent the establishment of pregnancy. These findings do not support the hypothesis that emergency contraception with LNG prevents pregnancy by interfering with post-fertilization events.
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    The expression of αv and β3 integrin subunits in the normal human Fallopian tube epithelium suggests the occurrence of a tubal implantation window
    (1998) Sülz, L; Valenzuela, JP; Salvatierra, AM; Ortiz, ME; Croxatto, HB
    The co-expression of alpha(1)beta(1), alpha(4)beta(1) and alpha(nu)beta(3) integrins in the human endometrium coincides with the implantation window The alpha(nu)beta(3) integrin is expressed in the apical surface of the luminal epithelium and may serve to anchor trophoblast cells in the adhesion phase of implantation. Using immunohistochemistry, we compared the expression of alpha, alpha(1), alpha(4) and beta(3) integrin subunits in samples of normal human Fallopian tube and endometrium obtained from five women in the non-receptive period (luteal phase days 2-4) and from another five women in the receptive period (luteal phase days 6-8), The staining was quantified visually on a scale of 0 to ++, according to the intensity and density of stained cells. The alpha(nu) subunit is expressed in the Fallopian tube epithelium during both periods in a pericellular distribution. The beta(3) subunit is also expressed in the same location, but it is up-regulated during the period of endometrial receptivity, The other subunits are expressed in localizations which are not relevant to trophoblast adhesion and exhibit little or no difference in the level of expression between the non-receptive and receptive periods. Based on these results we postulate that the expression of the beta(3) subunit in the human tubal epithelium is under the same systemic controlling signals as in the endometrium and that the normal tubal epithelium may have an implantation window, at about the same time as the endometrium, that affords the opportunity for trophoblast attachment should a 5-7 day embryo be unduly retained in the tube.