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OBJECTIVE To determine whether delivery can be predicted using transabdominal uterine electromyography. METHODS A total of 99 patients were grouped as either term (37 weeks or more) or preterm (less than 37 weeks). Uterine electrical activity was recorded for 30 minutes in clinic. Electromyographic "bursts" were evaluated to determine the power density(More)
Nitric oxide (NO) is considered to be an important local mediator that suppresses uterine contractility in rats and rabbits during pregnancy until term. The aim of this study was to investigate the mRNA concentrations for the three isoforms of nitric oxide synthase (NOS) in rat uterus and cervix and to determine whether alterations occur in association with(More)
OBJECTIVE To validate the possibility that human uterine electrical events (electromyographic signals) can be recorded and characterized from the abdominal surface during pregnancy. METHODS The gestational ages ranged from 20 to 43 weeks. The study included patients at term but not in labor, patients in active labor (term and preterm), postpartum(More)
Morphometric measurements at the electron microscope level were carried out on three categories of mesenteric arteries representing elastic (superior mesenteric), muscular and arteriolar vessels, from 10- to 12-week-old spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto normotensive rats (WKY). Changes were observed only in muscular and(More)
OBJECTIVE Power spectrum (PS) of uterine electromyography (EMG) can identify true labor. EMG propagation velocity (PV) to diagnose labor has not been reported. The objective was to compare uterine EMG against current methods to predict preterm delivery. STUDY DESIGN EMG was recorded in 116 patients (preterm labor, n = 20; preterm nonlabor, n = 68; term(More)
Presently, there is no effective treatment for preterm labor. The most obvious reason for this anomaly is that there is no objective manner to evaluate the progression of pregnancy through steps leading to labor, either at term or preterm. Several techniques have been adopted to monitor labor, and/or to diagnose labor, but they are either subjective or(More)
The hypothesis that gap junction (GJ) formation between myometrial cells at term improves electrical coupling was tested. We measured the spread of electrical excitation from six extracellular electrodes aligned on uterine strips in either the longitudinal (axial) or transverse (circumferential) direction. Spontaneous bursts propagated over the entire 15-mm(More)
Gap junctions between smooth muscle cells of the myometrium of pregnant rats were found only immediately prior to, during and immediately after parturition by quantitative thin-section and freeze-fracture microscopy. Ovariectomy of 16- to 17-days-pregnant rats resulted in premature termination of pregnancy and the appearance of gap junctions. Methods that(More)
Current methodologies to assess the process of labor, such as tocodynamometry or intrauterine pressure catheters, fetal fibronectin, cervical length measurement and digital cervical examination, have several major drawbacks. They only measure the onset of labor indirectly and do not detect cellular changes characteristic of true labor. Consequently, their(More)
Previously, we demonstrated the presence of an L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway in the rat uterus and that NO inhibits contractility during pregnancy but not during delivery. In the present study, we investigated the possible role of sex steroid hormones in the regulation of NO synthesis and cGMP generation. NO,(More)