Infección cervicovaginal como factor de riesgo para parto pretérmino / Cervicovaginal infection as a risk factor for premature labor

OBJECTIVE: To identify the possible association between cervicovaginal infections (CVI) and preterm delivery. DESIGN: Cohorts. REFERENCE FRAME: Instituto Nacional de PerinatologÝa, Hospital Central Militar and Hospital General Regional No. 1, IMSS, Culiacßn, Sinaloa, MÚxico. PATIENTS: Four hundred and sixty eight patients attending prenatal control and delivery care. INTERVENTIONS: Fresh smears, Gram stain, and cervicovaginal sample culture from samples obtained during the following gestational stages: First sample at 16-24 weeks, second sample at 25-32 weeks, and third sample at 33-42 weeks. The following microorganisms were studied: Candida albicans, Gardnerella vaginalis, Ureaplasma urealyticum, Streptococcus agalactiae, Mycoplasma hominis, Neisseria gonorrhoeae, Listeria monocytogenes, and Chlamydia trachomatis. In case of a positive culture, the specific treatment was indicated. MEASUREMENTS: Positive or negative culture for each of the studied pathogens, and the presence or absence of a preterm delivery for each of the patients included in the study. RESULTS: Three hundred and ninety eight were still present at the end of the study, of which 156 had a CVI and 242 had no CVI. No differences between both groups were observed concerning preterm delivery. Significant relative risks were: In the first stage, Ureaplasma urealyticum and Mycoplasma hominis with RR = 9.0 (6.81, 11.8); in the second stage, Ureaplasma urealyticum with RR = 6.2 (3.30, 11.7) and Escherichia coli with RR = 3.4 (1.33, 8.6); in the third stage, Ureaplasma urealyticum with RR = 9.19 (6.93, 12.1). The logistic regression analysis identified Ureaplasma urealyticum during the second stage with OR = 16.6 (2.9, 93.7), statistically significant with p = 0.001. The survival analysis showed differences between the two groups concerning pregnancy duration (p < 0.001). CONCLUSIONS: There is a difference in the duration in pregnancy in patients with CVI and without CVI. Ureaplasma urealyticum is consistently associated with preterm delivery.

Caracterización bioquímica y ultraestructural del efecto de la interleucina 1-beta como mediador de degradación de tejido conectivo en membranas corioamnióticas humanas en cultivo / Biochemical and ultrastructural characterization of the effect of interleukin 1-beta as mediator of the degradation of connective tissue in human chorioamniotic membranes in culture

OBJECTIVE: To characterize the effect of IL-1 beta, on connective tissue metabolism in a human chorioamniotic membrane tissue culture (CAM). TYPE OF STUDY: Experimental, in an in vitro model. MATERIAL AND METHODS: CAM explants obtained from cesarean sections were cultured. The presence of local infection was excluded by microbiological methods. An XTT viability essay of the explants was carried out. Explants were stimulated with different doses of IL-1 beta within a 0-10 ng/mL range. After the stimulation, protein content was measured, MMP-9 production was determined by zymography, and each explant was divided in two parts: one was used for collagen measurement and the other analyzed by electronic microscopy. RESULTS: CAMs kept adequate viability and functionality. IL-1 beta stimulation produced an increase in the amount of MMP-9 expressed, as determined by the zymography method with a maximum effect 36 hours after stimulation. Collagen content decreased in a progressive manner after IL-1 beta stimulation and reached its minimum after 36 hours. The characteristic pattern of collagen fibers gradually lost its organization, and could not be observed any more after 36 hours. CONCLUSIONS: The information presented here allows us to conclude that IL-1 beta is capable of inducing an enzymatic expression affecting connective tissue, thus confirming its participation in membrane degradation processes under inflammatory conditions.

Alteración de la respuesta inmunológica sistémica en asociación con endometriosis, empleando un modelo de estudio animal / Changes in the systemic immunologic response in association with endometriosis using an animal model

INTRODUCTION: Endometriosis constitutes the growth of endometrial tissue in a place other than the uterine cavity. Its etiopathogenesis is unknown, although there is some evidence associating it with the decrease of cytotoxic activity in the immunological system. OBJECTIVE: Evaluating the relationship between the development of ectopic endometrial tissue and the immunological status, and enumerating lymphocyte subpopulations and cytokine synthesis in T lymphocytes, using a murine endometriosis model. METHODOLOGY: Spleen lymphocytes isolated from two study groups of 10 female mice of the Balb/c strain that had been submitted to the surgical implantation of autologous endometrial tissue in the peritoneal cavity, and sacrificed after 5 (group I) and 8 (group II) weeks, were incubated--or not--with PMA/lonomicine. Lymphocyte T numbers and their cytokine production were determined by flow cytometry. RESULTS: A lower dispersion of the ectopic tissue growth value was observed in group II (24 vs. 42). A smaller population of cytotoxic T lymphocytes and a greater IL-4 production in the stimulated cells of the study group (p < 0.05) were observed, as compared to the control group. CONCLUSIONS: The presence of endometrial tissue in the uterine cavity decreases the amount of cytotoxic T lymphocytes and increases IL-4 production in total T lymphocytes, suggesting a modulation of the systemic immunological response to TH-2.