Lynette B. MacKay

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Parturition is preceded by a large increase in gap junctions between myometrial smooth muscle cells. Connexin 43 is the major structural protein of myometrial gap junctions. To explore transcriptional regulation of the myometrial Cx43 gene, we used DNase I footprinting, electrophoretic mobility shift and transient transfection assays to examine a 312 bp(More)
Gap junctions between myometrial cells increase dramatically during the final stages of pregnancy. To study the functional consequences, we have applied the double-whole-cell voltage-clamp technique to freshly isolated pairs of cells from rat circular and longitudinal myometrium. Junctional conductance was greater between circular muscle-cell pairs from(More)
This study examines the relationship between inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the control of cervical ripening and parturition under normal (normal term pregnancy) and abnormal (preterm labor and prolongation of pregnancy) conditions by (a) measuring changes in the collagen both visually and quantitatively, (b)(More)
The physiologic and pathologic changes of the uterine cervix during pregnancy leading to cervical ripening are not well understood though are related to the chief pathology and a commonly performed intervention in obstetrics: Preterm birth and labor induction. Normal cervical ripening is thought to be controlled by a variety of hormonal changes occurring(More)
The present work seeks to determine if a particular non-linear analytic method is effective at quantifying uterine electromyography (EMG) data for estimating the onset of labor. Twenty-seven patients were included, and their uterine EMG was recorded non-invasively for 30 min. The patients were grouped into two sets: G1: labor, N=14; G2: antepartum, N=13. G1(More)
To understand cervical ripening and especially the pathophysiology of cervical insufficiency, it is important to know the cervical composition: the cervix is dominated by fibrous connective tissue, consisting predominantly of Type I collagen (70%). Despite many studies of the cervix, we still rely upon relatively crude methods for clinical evaluation of the(More)
OBJECTIVE The electrophysiologic properties of gap junctions between human myometrial smooth muscle cells were studied. STUDY DESIGN Double whole-cell patch clamp recordings were made on pairs of cells from primary cultures of myometrial cells from women undergoing cesarean section. Macroscopic gap junction currents were measured as the change in current(More)
OBJECTIVE This study was undertaken to use artificial neural networks on uterine electromyography data to identify term and preterm labor in rats. STUDY DESIGN Controls (group 1: n = 4) and preterm labor models (group 2: n = 4, treated with onapristone) were used. Uterine electromyography and intrauterine pressure (IUP) variables were measured by(More)
AIMS To determine the effect of bilateral pelvic neurectomy (BPN) on cervical ripening in pregnant rats by measuring cervical extensibility and changes in collagen cross-linkages. METHODS Timed-pregnant rats were randomly laparotomized on days 9 or 10 of gestation and the pelvic nerves were exposed and either bilaterally transected, or left intact in sham(More)
OBJECTIVE Our goal was to test the hypothesis that the previously demonstrated progesterone-independent prolongation of pregnancy in rats treated with cervical application of the cyclooxygenase 2 inhibitor nimesulide is the result of inhibition of cervical ripening. STUDY DESIGN Timed-pregnant Sprague-Dawley rats were randomly allocated to treatment with(More)