Biomedical subjects

W F O'Brien

Publications and source records attributed to W F O'Brien.

At least 19 recordsLinked to original sources

PubMed2001

Safety and efficacy of misoprostol orally and vaginally: a randomized trial.

OBJECTIVE: To compare the safety and efficacy accompanying oral and vaginal misoprostol for cervical ripening. METHODS: One thousand four women with medical or obstetric indications for labor induction and unripe cervices were randomly assigned to receive oral or vaginal misoprostol. Initial doses of 200 microg oral and 50 microg vaginal misoprostol were increased to 300 microg oral and 100 microg vaginal after two doses, to a maximum of six doses. Misoprostol was given every 6 hours in both groups. We anticipated that 11% of women treated vaginally would require intervention during the ripening process. Intervention was defined as interruption of the ripening process before labor or Bishop score of 7 or a lack of response to six misoprostol doses. RESULTS: Five hundred three subjects were assigned to oral and 501 to vaginal administration. Oral misoprostol was associated with significantly higher frequencies of intervention (67 [13.3%] versus 42 [8.4%], P =.01), tachysystole (114 [23.6%] versus 85 [17.6%], P =.02), and hyperstimulation (90 [18.6%] versus 66 [13.7%], P =.04). There were no significant differences in cesarean rates (147 [29.2%] versus 120 [24.0%], P =.06), mean number of misoprostol doses used (1.5 versus 1.6, P =.18), or hours from drug administration to delivery (24.5 versus 25.4, P =.77) between the oral and vaginal groups, respectively. The numbers of deliveries between the groups within 24 hours was different (271 [56%] versus 290 [60%], P =.02), oral and vaginal, respectively. No adverse neonatal outcomes were noted. CONCLUSION: Oral misoprostol has similar efficacy as vaginal misoprostol but is associated with a higher frequency of excessive uterine contractility and intervention.

Administration, Intravaginal↗

PubMed2001

Sulindac to prevent recurrent preterm labor: a randomized controlled trial.

OBJECTIVE: To assess the efficacy of oral sulindac in low doses for prolonged duration to decrease the risk of recurrent preterm labor and extend gestation. METHODS: This was a randomized, double-blind, placebo-controlled study of patients between 24 and 34 weeks' gestation with preterm labor treated with intravenous magnesium sulfate. After successful tocolysis, patients were randomized by the pharmacy to receive either oral sulindac (100 mg) or placebo orally every 12 hours until 34 weeks' gestation. A power analysis required 43 patients in each group. RESULTS: Ninety-five patients were enrolled (46 in the sulindac group, 49 controls). No significant differences were found with respect to time gained in utero (39 +/- 25 versus 45 +/- 26 days, P = .29), delivery at more than 35 weeks' gestation (61% versus 74%, P = .29), recurrent preterm labor (20% versus 18%, P = .86), birth weight (2562 +/- 623 versus 2624 +/- 543 g, P = .62), or time spent in the neonatal intensive care unit (2.8 +/- 9.2 versus 2.4 +/- 8.6 days, P = .83) for the sulindac and control groups, respectively. CONCLUSION: The use of oral sulindac until 34 weeks' gestation after successful parenteral tocolysis failed to reduce the incidence of readmission for preterm labor.

Administration, Oral↗

PubMed2001

Tuberculosis in North Carolina: trends across two decades, 1980-1999.

In North Carolina, we analyzed cumulative data for tuberculosis (TB) from 1980 through 1999 to determine trends in incidence, population subgroups at risk, and implications for health policy- makers. The overall incidence rates declined significantly over the study period (p = 0.0001). This decline correlates strongly with an increase in TB patients receiving directly observed therapy. Males have approximately twice the risk for disease, and persons >65 years of age are at the highest risk. For every Caucasian with TB, six blacks, six Hispanics, and eight Asians have the disease. TB incidence rates are declining in all other population subgroups but increasing in foreign-born and Hispanic persons.

Adolescent↗

PubMed2000

Histologic chorioamnionitis is associated with fetal growth restriction in term and preterm infants.

OBJECTIVE: Our aim was to evaluate associations between chorioamnionitis and fetal growth restriction in infants enrolled in the Collaborative Perinatal Project. STUDY DESIGN: A total of 2579 nonanomalous, singleton infants delivered at 28 to 44 weeks' gestation with chorioamnionitis were matched 1:3 for ethnicity, gestational age, parity, and maternal cigarette use (all of which were correlated with both chorioamnionitis and markers of fetal growth restriction) with 7732 control infants. Moderate or marked leukocytic infiltrates of the placenta defined chorioamnionitis. Birth weight, length, head circumference, weight/length ratio, ponderal index, and birth weight/head circumference ratio in the lowest 5th percentile were markers of fetal growth restriction. Placental weight and the birth weight/placental weight ratio were also evaluated. RESULTS: Compared with data on matched control infants, histologic chorioamnionitis was associated with all markers of fetal growth restriction and with low birth weight/placental weight ratios (odds ratios, 1.3-1.7). The strongest associations were found at 28 to 32 weeks' gestation (odds ratios, 2.2-11). Attributable risks for several markers of fetal growth restriction exceeded 50% in infants born at <33 weeks' gestation. CONCLUSION: Histologic chorioamnionitis is associated with multiple markers of fetal growth restriction, with stronger associations noted in prematurity.

Adult↗

PubMed2000

Corticotropin-releasing hormone increases the expression of the prostaglandin E(2) receptor subtype EP1 in amnion WISH cells.

The purpose of this study was to investigate the effect of corticotropin-releasing hormone (CRH) on the expression of the prostaglandin (PG) E(2) EP1 receptor subtype and PGE(2) production in amnion WISH cells (AWC). AWC cultures were incubated with CRH. Culture fluid was collected for PGE(2) measurement, and the cells were collected and analyzed for EP1 protein and mRNA. Immunohistochemical localization of the EP1 receptor was also performed. Incubation of AWC with CRH resulted in a dose-dependent increase (r = 0.97) in the level of EP1 receptor protein (P < 0.001). Coincubation of AWC with CRH and indomethacin resulted in the decreased production of PGE(2) while having no effect on EP1 receptor expression. A significant but not dose-dependent increase in EP1 mRNA expression was also observed (P < 0.01). Immunohistochemical evaluation verified cell membrane localization of the receptor in both stimulated and unstimulated cells and confirmed the increased expression of EP1 receptor in response to CRH. Incubation of AWC with CRH also resulted in increased culture fluid PGE(2) levels (P < 0.01). These results suggest that the role CRH plays in the initiation of labor may also involve the promotion of elevated PGE(2) levels and increased expression of the EP1 receptor in amnion.

Amnion↗

PubMed1999

Human uterine leiomyomata express higher levels of peroxisome proliferator-activated receptor gamma, retinoid X receptor alpha, and all-trans retinoic acid than myometrium.

Uterine leiomyomata are the main indication for a hysterectomy in the United States and occur in 25% of women >35 years. Because uterine leiomyomata can form when ovariectomized guinea pigs are exposed to estradiol and retinoic acids, we tested whether human leiomyomata had high levels of retinoic acids and related nuclear receptors. Compared with normal human myometrium, leiomyomata had 3- to 5-fold higher levels of peroxisome proliferator-activated receptor gamma (PPARgamma), retinoid X receptor alpha proteins, and all-trans retinoic acid, but only during the follicular phase of the menstrual cycle. 9-cis Retinoic acid was undetectable in either leiomyomata or myometrium. PPARgamma mRNA levels were lower in leiomyomata than myometrium, but only during the luteal phase of the cycle. A PPARgamma agonist, troglitazone, was given to guinea pigs along with estradiol and all-trans retinoic acid and produced the largest leiomyomata seen to date in this model. By contrast, no tumors formed when troglitazone was given alone or with estradiol or when troglitazone was given with estradiol and 9-cis retinoic acid. New therapies for human leiomyomata may emerge by combining antagonists for PPARgamma and retinoid X receptor alpha with selective estrogen receptor modulators.

Alitretinoin↗

PubMed1999

Modulation of the prostaglandin E receptor: a possible mechanism for infection-induced preterm labor.

OBJECTIVE: To evaluate the modulatory effects of interleukin (IL)-1beta and prostaglandin (PG)E2 on the PGE2 receptor subtype EP1 in amnion cell cultures. METHODS: Amnion cell cultures were incubated in increasing concentrations of (IL)-1beta or PGE2. Cultures were also incubated in high concentrations of IL-1beta and PGE2 in combination. Changes in EP1 receptor levels were evaluated by western and northern blot analysis. Culture fluid PGE2 levels were measured by enzyme-linked immunosorbent assay. RESULTS: EP1 receptor protein levels decreased with increasing levels of PGE2 (r = -0.82, P < .05). EP1 receptor protein (r = 0.95, P < .05), EP1 mRNA (r = 0.95, P < .01), and culture fluid PGE2 levels (P < .01) were all increased after IL-1beta administration. EP1 receptor levels also increased approximately fourfold in response to IL-1beta incubation even in the presence of high agonist (PGE2) concentrations (P < .01). CONCLUSION: The results of this study show that IL-1beta might be involved in infection-induced preterm labor by interfering with the normal regulation of EP1 receptor levels and with the promotion of increased PGE2 production in amnion tissue.

Cells, Cultured↗

PubMed1999

Immunohistochemical localization of the prostaglandin E subtype-1 receptor in cytokine-stimulated and unstimulated amnion cells.

OBJECTIVE: To visualize histochemically the prostaglandin EP1 receptor in human amnion cells and to study the effect of inflammatory cytokines, which are known to stimulate the EP1 receptor, on localization. METHODS: Immortalized amnion cells, grown on standard microscope slides and either nonstimulated (control) or stimulated by incubation in culture medium containing interleukin-1beta (25 ng/mL), interleukin-4 (50 ng/mL), or tumor necrosis factor alpha (25 ng/mL), were incubated with rabbit anti-human EP1 antibody and stained by a two-step indirect immunoperoxidase strepavidin-biotin method using horseradish peroxidase and 3,3' diaminobenzidine as the chromogen. The localization was done on ten different flasks of cells. Duplicate slides for each cytokine concentration were prepared. Negative controls for each reagent, prior blocking with 1% bovine serum albumin or 1% milk, or pretreatment with preimmune rabbit immunoglobulin G were run simultaneously. Slides were viewed by standard light microscopy with and without counterstaining with hematoxylin. RESULTS: Amnion cells incubated in medium alone showed receptor localization throughout the cytoplasmic region of the cell membrane. The localization was nonuniform; a discrete unipolar region of perinuclear nonlocalization was observed. Staining occurred in widely dispersed nests. Cytokine stimulation resulted in increased intensity of staining and an increase in the size of the positive nests; however, it did not affect the discrete unipolar perinuclear region of nonlocalization. CONCLUSION: Histochemical localization of the human EP1 receptor confirms a cytoplasmic identity and probable plasma membrane localization. Stimulation by inflammatory cytokines increases staining by recruitment of new amnion cells and appears to increase receptor density per cell.

Amnion↗

PubMed1998

Effects of raloxifene in a guinea pig model for leiomyomas.

OBJECTIVE: Chronic exposure of oophorectomized guinea pigs to 17beta-estradiol causes leiomyoma formation. Our aims were to determine whether these leiomyomas can become estradiol independent after exposure to estradiol and if raloxifene inhibits leiomyoma growth when given concomitantly with estradiol. STUDY DESIGN: To induce leiomyoma development, 6 oophorectomized animals received two estradiol implants for 140 days. Next, the estradiol implants were replaced with empty implants in 3 animals, whereas the other 3 received 2 new estradiol implants and raloxifene given per os 10 mg/kg per day for 60 days. Tumor size was monitored biweekly by ultrasonography. RESULTS: On estradiol removal, abdominal wall leiomyomas regressed within 15 to 30 days; when estradiol implants were reintroduced, leiomyomas redeveloped. Within 30 days on raloxifene, all abdominal leiomyomas (n = 9) regressed as determined by ultrasonography and verified at laparotomy. Serum raloxifene and estradiol levels were 432 +/- 46 pg/mL and 78 +/- 13 pg/mL (mean +/- SEM, n = 3), respectively, after 60 days of treatment. CONCLUSIONS: Leiomyomas did not become estradiol independent, even after long exposure to estradiol; ultrasonography allowed frequent, noninvasive assessment of leiomyoma size, and raloxifene rapidly regressed leiomyomas in this animal model.

Animals↗

PubMed1998

The induction of cyclooxygenase-2 by interleukin-4 in human umbilical vein endothelial cells: a possible role in regulation of fetal vascular tone.

OBJECTIVE: We sought to determine a possible role for interleukin-4 in the control of umbilical cord blood flow by evaluating its effect on cyclooxygenase-2 production of a vasoactive prostaglandin. STUDY DESIGN: Human umbilical vein endothelial cells in culture were incubated for 16 hours in media containing interleukin-4 in concentrations from 5 to 100 ng/ml. Prostaglandin E2 concentrations in the culture media were measured using a monoclonal enzyme-immunoassay. Concentrations of cyclooxygenase-1 and cyclooxygenase-2 were determined by Western blot analysis on cell homogenates. Statistical comparisons between prostaglandin E2, cyclooxygenase-1, and cyclooxygenase-2 concentrations for each interleukin-4 concentration were performed using a one way analysis of variance. RESULTS: Incubation of human umbilical vein endothelial cells in media containing interleukin-4 resulted in a significant increase in both prostaglandin E2 and cyclooxygenase-2 for interleukin-4 concentrations greater than 50 ng/ml (p < 0.05). Cyclooxygenase-1 levels were not affected. CONCLUSIONS: We suggest that interleukin-4 may have a role in the regulation of umbilical blood flow mediated through the induction of cyclooxygenase-2.

Blotting, Western↗

PubMed1998

Persistent pulmonary hypertension of the neonate and asymmetric growth restriction.

OBJECTIVE: To evaluate the possible associations between persistent pulmonary hypertension of the neonate, need for extra-corporeal membranous oxygenation, small for gestational age (SGA), and low ponderal index for gestational age in infants with persistent pulmonary hypertension of the neonate and in matched controls. METHODS: Eighty-six infants with persistent pulmonary hypertension of the neonate delivered from 1991 to 1994 at our hospital were matched with 430 contemporaneous control singleton neonates. Birth weight and ponderal indices (100 x weight/length3) less than the tenth percentile for gestational age and gender were defined as SGA and low ponderal index, respectively. We assessed associations between these markers, the presence of persistent pulmonary hypertension of the neonate, and the need for extracorporeal membranous oxygenation. RESULTS: Low ponderal index was associated with persistent pulmonary hypertension of the neonate (odds ratio [OR] 5.4), whereas SGA was not. Low ponderal index (OR 4.0) was an independent correlate of persistent pulmonary hypertension of the neonate after adjustment with logistic regression for 5-minute Apgar scores less than 7, umbilical arterial pH less than 7.10, and presence of meconium. Low ponderal index was associated with need for extracorporeal membranous oxygenation in neonates with persistent pulmonary hypertension (P < .001). CONCLUSION: Fetal developmental events may significantly affect neonatal pulmonary status. Diminished neonatal nutritional status, as measured by low ponderal index for gestational age, is associated with increased risk of persistent pulmonary hypertension of the neonate and severity of the disease process.

Case-Control Studies↗

PubMed1998

Low weight/length ratio to assess risk of cerebral palsy and perinatal mortality in twins.

The etiology of increased rates of cerebral palsy (CP) in twins is unclear, but likely is associated with growth retardation, which occurs more often in twins. Asymmetric growth restriction, a form of growth retardation, has been found associated with increased rates of perinatal morbidity in infants with normal centile birthweights, and occurs more often in twins. Data from 55,457 infants were evaluated. Associations between twinning, CP, and neonatal mortality were evaluated. Influences of confounding factors, such as prematurity, perinatal depression, and asymmetric growth were assessed. Although twinning was a significant univariate correlate of both CP and neonatal mortality, low weight/length ratio (a marker of asymmetric growth) was a better correlate of both outcomes, and twinning was not significantly associated with either outcome after logistic adjustment for factors such as prematurity, perinatal depression, and low weight/length ratio. Low weight/length ratio occurred more often in twins of advancing gestational age, supporting a hypothesis of competition for nutritional resources as the cause for increased rates of low weight/length ratio in twins as compared with singletons. Asymmetric growth restriction is an important correlate of neonatal morbidity in twins, and should be considered when these factors are assessed in infants from multiple gestations.

Birth Weight↗

PubMed1998

Are maternal diabetes and preeclampsia independent simulators of fetal erythropoietin production?

To determine if diabetes and preeclampsia are independent stimulators of erythropoietin, distinct from hypoxia, we measured umbilical cord plasma erythropoietin in 239 deliveries from 24 to 40 weeks of gestation. Mean plasma erythropoietin levels were not different between normal, diabetic, and preeclamptic women when all deliveries were analyzed. When infants with suspected intrauterine hypoxia were excluded, the mean erythropoietin level was considerably lower within all three groups but there was no difference among the groups. In suspected hypoxia, the mean fetal erythropoietin was elevated, but there was no difference between control, diabetic, or preeclamptic pregnancies. These results provide further support that hypoxia remains the only known stimulator of erythropoietin production in the fetus.

Erythropoietin↗

PubMed1998

Tumor necrosis factor-alpha upregulates the prostaglandin E2 EP1 receptor subtype and the cyclooxygenase-2 isoform in cultured amnion WISH cells.

Recent studies have demonstrated a strong correlation between infection and preterm labor. Preterm delivery is also associated with high levels of cytokines and prostaglandins in amniotic fluid. The purpose of this study was to investigate the effect of tumor necrosis factor-alpha (TNF-alpha) on the levels of cyclooxygenase, prostaglandin E2 production (PGE2), and expression of the PGE2 receptor subtype EP1 in amnion WISH cell culture. Amnion WISH cell cultures were incubated in increasing concentrations of TNF-alpha (0-50 ng/ml). Changes in cyclooxygenase and EP1 receptor proteins were evaluated by Western blot analysis. Changes in EP1 mRNA were evaluated by Northern blot, and culture fluid concentrations of PGE2 were estimated by enzyme immunoassay (EIA). EP1 protein (p<0.01), EP1 mRNA (p<0.05), cyclooxygenase-2 (COX-2) protein (p<0.001), and PGE2 concentrations (p<0.01) all increased with increasing concentrations of TNF-alpha. Changes in COX-1 protein were not observed following TNF-alpha-incubation. The results suggest that TNF-alpha may play a role in infection-induced preterm labor by its pleiotropic ability to simultaneously stimulate COX-2 activity, PGE2 concentrations, and PGE2 EP1 receptor levels in human amnion.

Amnion↗

PubMed1997

Effect of intramuscular 15-methyl prostaglandin F2 alpha after second-trimester delivery.

OBJECTIVE: To determine whether 15-methyl prostaglandin (PG) F2 alpha shortens the third stage of labor in second-trimester pregnancy loss. METHODS: This was a randomized, double-blind, placebocontrolled study of women between 13 and 28 weeks' gestation admitted for spontaneous or induced pregnancy termination. Subjects were randomized on admission to receive either PG (250 micrograms) or placebo (normal saline), 1 mL intramuscularly every 20 minutes, for a maximum of three doses if the placenta had not delivered spontaneously within 10 minutes of the fetus. A dilute oxytocin infusion was given to women in both groups. The patients were managed expectantly with hourly vaginal examinations until intervention was required or up to 6 hours, when curettage was scheduled. RESULTS: Thirty-eight women received PG and 29 received placebo. There was no difference between the groups with regard to method of pregnancy termination or gestational age. There was a statistically significant decrease in the time from first injection to placental delivery (40.0 versus 92.5 minutes; P = .02) between the PG and control groups, respectively. CONCLUSIONS: The therapeutic use of PG in the third stage of labor in second-trimester pregnancy loss reduces the time to complete spontaneous placental delivery.

Dinoprost↗

PubMed1997

Randomized trial of endovaginal ultrasound in preterm premature rupture of membranes.

OBJECTIVE: To assess the effect of weekly endovaginal ultrasound on the incidence of maternal infection and the time from rupture to delivery in women with preterm premature rupture of membranes (PROM). METHODS: Women with singleton pregnancies complicated by preterm PROM at 24-34 weeks' gestation were assigned randomly to groups having endovaginal ultrasound or no vaginal sonography. Along with the standard expectant management, the endovaginal-ultrasound group had weekly vaginal probe ultrasound scans. Power analysis based upon expected maternal infection required a sample size of 45 patients in each group. RESULTS: Forty-seven and 45 subjects were assigned to the no-probe and probe groups, respectively. The latency period, defined as days from rupture to delivery, was 9.8 and 11.7 days for the no-probe and probe groups, respectively (95% confidence interval -5.9, 2.1). There were no significant differences in the incidence of chorioamnionitis (28% and 20%), endometritis (6% and 9%), or neonatal infection (17% and 20%). The mean latency period in women who went into spontaneous labor and whose initial cervical length was 3.0 cm or less was 9.4 days, compared with 11.0 days if the cervix exceeded 3.0 cm, a nonsignificant difference. There were three neonatal deaths, all in the probe group and none directly related to infection. CONCLUSIONS: Endovaginal ultrasound in patients whose pregnancies are complicated by preterm PROM does not appear to increase the incidence of maternal infection.

Chorioamnionitis↗

PubMed1997

The value of the cervical score in predicting successful outcome of labor induction.

OBJECTIVE: To compare cervical dilation and the Bishop score as correlates of successful labor induction and vaginal delivery and to determine whether the prognosis of post-ripening cervical characteristics varies with the method of ripening used. METHODS: Four hundred forty-three women with Bishop scores less than 9 who required induction of labor were assigned randomly to cervical ripening with prostaglandin E2 gel or hygroscopic dilation. The Bishop score and its component characteristics were evaluated as univariate correlates of successful induction of labor and vaginal delivery and then were assessed using logistic regression to adjust for other maternal and fetal factors. The differences in the association between method of ripening and successful labor induction were evaluated relative to pre-ripening and post-ripening cervical examination characteristics. RESULTS: Cervical dilation was a better correlate of successful labor induction and vaginal delivery than was the Bishop score, even after exclusion of patients with initial Bishop scores greater than 6 and dilation greater than 3.0. Both ripening methods yielded similar success in labor induction and vaginal delivery, but when categorized by post-ripening cervical examinations, patients undergoing hygroscopic ripening had lower rates of successful labor induction and vaginal delivery. CONCLUSION: Cervical dilation is a better predictor of successful labor induction and vaginal delivery than either the Bishop score or any other Bishop score component characteristic. The likelihood of successful labor induction and vaginal delivery based on post-ripening cervical characteristics varies by the ripening method used.

Cervix Uteri↗

PubMed1997

Extemporaneous preparation of misoprostol gel for cervical ripening: a randomized trial.

OBJECTIVE: To compare the safety and efficacy of intravaginal misoprostol gel with that of tablets for ripening the cervix and inducing labor in women with unfavorable cervices. METHODS: Four hundred sixty-seven gravidas were randomized to receive misoprostol tablets (n = 234) or misoprostol gel (n = 233). The gel was prepared in the antepartum unit immediately before use by dissolving the tablet in 1 mL normal saline and mixing with 4 mL hydroxyethylcellulose gel. In both groups, a 50-microgram dose was applied intravaginally every 8 hours for two doses, then increased to 100-microgram for a total of six applications or 500 micrograms. RESULTS: The mean interval in hours from drug administration to start induction or labor (13.8 versus 18.2) and delivery (22.4 versus 29.0) was significantly less in the tablet group than in the gel group (P < .01 for both). Oxytocin and epidural use and the mean number of misoprostol insertions (1.4 versus 1.9) were lower in the tablet group than in the gel group (P < .05 for all). The incidences of tachysystole (13.7 versus 7.3%) and hyperstimulation (15.8 versus 7.7%) were significantly higher in the tablet group than in the gel group. Cesarean delivery rates and neonatal outcomes were similar between the groups. CONCLUSION: Intravaginal misoprostol gel is associated with fewer uterine contractile abnormalities than the tablet form of the drug but results in a slower time to labor or delivery.

Administration, Intravaginal↗