Browsing by Author "Vigil, P"

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    First-trimester pregnancy loss and active Chlamydia trachomatis infection
    (2002) Vigil, P; Tapia, A; Zacharias, S; Riquelme, R; Salgado, AM; Varleta, J
    The incidence of Chlamydia trachomatis (Ct) infection and the possible correlation between couples presenting with first-trimester spontaneous abortions and active Ct infection was assessed. Additionally, the ability of Ct to infect zona-free hamster oocytes was explored by incubating the oocytes with spermatozoa from infected patients. A total of 961 women and 750 men consulting our reproductive medicine centre were screened for Ct using direct immunofluorescence. The general incidence of Ct infection was 9.4% in females ( 90 of 961) and 13.9% in males ( 104 of 750). In women with spontaneous abortions the incidence of Ct was 21.0% ( 14 of 66) compared with 8.9% ( 23 of 59) for women without spontaneous abortions and term pregnancies (chi-square, P < 0.05). When both partners of the couples were considered ( one or both partners infected), the incidence rose to 68.8% ( 22 of 32) (chi-square, P < 0.001). In vitro studies using electron microscopy demonstrated the presence of Ct on the surface of and inside the oocyte. These results indicate a correlation between an active Ct infection and spontaneous abortion. Electron microscopy studies suggested the possibility of direct oocyte infection by Ct. Two models are proposed for the pathogenesis of Ct-related early abortions: ( i) direct zygote infection, and (ii) immune response to heat shock proteins expressed by the zygote and triggered by previous Ct infections.
  • No Thumbnail Available
    Item
    Hormonal monitoring of ovarian activity using the Ovarian Monitor, Part 1. Validation of home and laboratory results obtained during ovulatory cycles by comparison with radioimmunoassay
    (2003) Blackwell, LF; Brown, JB; Vigil, P; Gross, B; Sufi, S; d'Arcangues, C
    A study was conducted to determine the accuracy and reliability of the Home Ovarian Monitor for measuring estrone glucuronide (E1G) and pregnanediol glucuronide (PdG) during ovulatory cycles as a means of monitoring ovarian activity. Approximately 60 ovulating women in three centres collected timed specimens of urine (3 h or more) for a total of six cycles each. The women measured the E 1 G and PdG excretion per 24 h in their urine specimens using the Monitor. A local laboratory using the Monitor also measured the excretion. Urine specimens from 18 to 19 cycles were sent frozen to the WHO Reference Laboratory in London where they were analysed for E1G and PdG by the Monitor and by radioimmunoassay (RIA). The correlation coefficients between the Monitor and radioimmunoassay results obtained in London were better than 0.84 in 80% of the cycles. A urine bias caused the Monitor E1G results to be higher than those obtained by radioimmunoassay but the daily patterns were the same. In 50% of the cycles, this bias caused a delay of up to 3 days in identifying the beginning of the El G rise compared with radioimmunoassay. Timing of the preovulatory El G peak and the postovulatory PdG rise agreed within the experimental errors of the two systems. The study confirmed that women using the Monitor at home obtained results that were as accurate as those obtained by laboratory procedures. Careful supervision was required to maintain laboratory levels of quality control and interpretation of results. (C) 2003 Elsevier Science Inc. All rights reserved.
  • No Thumbnail Available
    Item
    Chlamydia trachomatis infection in male partners of infertile couples
    (2002) Vigil, P; Morales, P; Tapia, A; Riquelme, R; Salgado, AN
    Chlamydia trachomatis infection is one of the most common sexually transmitted diseases. Its effect on male fertility, however, is still controversial. In this study, 284 male partners of infertile couples consulting the Center of Studies in Reproductive Biology (CEBRE) were analyzed. The incidence of C. trachomatis infection among male partners of infertile couples was 38.6%. There were no significant differences between infected and noninfected infertile men in any of the sperm parameters assessed (sperm concentration. motility and morphology). The results of the three bioassays developed to evaluate sperm physiology, namely spermatozoazona pellucida binding. acrosome reaction stimulated with human follicular fluid and zona-free hamster oocyte penetration, showed no differences between infected and noninfected men. Electron microscopy studies suggest that spermatozoa are active agents in the dissemination of the chlamydial infection; they could be acting as 'vehicles' for the pathogens. These, and other results. suggest that the possible effect of C. trachomatis on male fertility is not due to alterations in sperm 'quality' or function, but rather to the transmission of the disease to female partners, causing inflammatory processes and promoting the generation of antisperm antibodies.
  • No Thumbnail Available
    Item
    In vivo and in vitro estrogenic and progestagenic actions of Tibolone
    (2005) Sadarangani, A; Salgado, AN; Kato, S; Pinto, M; Carvajal, A; Monso, C; Owen, GI; Vigil, P
    Estrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones would be clinically advantageous. However, data from the Million Women Study suggests that Tibolone increases the risk of both breast and endometrial cancer. Herein, we assessed the estrogenic and progestagenic actions of Tibolone using transvaginal sonography studies and an in vitro model of breast (ZR-75, MCF7) and endometrial cancer (Ishikawa). The known cancer associated proteins (ER, EGFR, STAT5, tissue factor and Bcl-xL) were selected for study. Transvaginal sonography demonstrated that postmenopausal women treated with Tibolone displayed a thinner endometrium than in the late proliferative phase, but had a phenotype characteristic of the secretory phase, thus demonstrating the estrogenic and progestagenic actions of this SERM. In vitro, Tibolone acted as an estrogen in downregulating ER and upregulating Bcl-xL, yet as progesterone, increasing STAT5 and tissue factor in breast cancer cells. The increase in tissue factor by Tibolone correlated with its coagulative potential. Interestingly, EGFR was Lip-regulated by progesterone in the breast and by estrogen in endometrial cells, while Tibolone increased protein levels in both cell types. In conclusion, this study further demonstrates the estrogenic and progestagenic nature of Tibolone. The pattern of regulation of known oncogenes in cells of breast and endometrial origin dictates caution and vigilance in the prescription of Tibolone and subsequent patient monitoring.