Cocaine affects prostaglandin production in human umbilical cord cell cultures.

OBJECTIVE: To investigate the possible effects of cocaine on prostacyclin and prostaglandin (PG) E2 production from endothelial cells derived from human umbilical cord. STUDY DESIGN: First-passaged endothelial cells derived from the umbilical vein were incubated with various doses of cocaine, procaine and lidocaine and 24 h later the supematants were assayed for prostacyclin metabolites 6-keto-PGF1alpha and PGE2. Cocaine concentrations tested were 0, 10, 100, 500 and 1000 microg/ml. RESULTS: Cocaine produced a dose-dependent reduction in prostacyclin and PGE2 production from endothelial cells (p) < 0.05). Acetylcholinesterase (a possible detoxifier of cocaine) abolished the effect of cocaine on prostacyclin production. Procaine, an esterol-type anesthetic, produced a similar effect on prostacyclin production, an effect not observed with lidocaine. CONCLUSION: It is speculated that, when present in high concentrations, cocaine may affect vascular tone by inhibition of endothelial cell prostacyclin and PGE2 release.

Cocaine decreases urinary prostacyclin release in pregnancy: correlation with uterine and umbilical Doppler velocimetry.

OBJECTIVE: The purpose of this study was to determine maternal urinary prostacyclin and thromboxane excretion in patients with recent cocaine use, compared to cocaine-free controls, and correlate the findings with Doppler velocimetry. STUDY DESIGN: Seventeen patients admitted with premature rupture of membranes between the gestational ages of 24 and 34 weeks were tested for urinary cocaine metabolites. Eleven patients had positive screening and six patients were negative and served as controls. After initial stabilization, 24-h urine collections were obtained and were assayed for the prostacyclin metabolite 2,3-dinor-6-keto-PGF(1alpha), and the thromboxane metabolite 2,3-dinor TXB2. These patients underwent uterine and umbilical arterial Doppler velocimetry expressed as the pulsatility index. Statistical analysis was performed by the SPSS statistical package using the non-paired Student t test, and Spearman correlation coefficient with p < 0.05 being considered significant. RESULTS: Compared with controls, urinary excretion of prostacyclin in pregnant women with recent cocaine use was significantly lower. The pulsatility index of the uterine arteries of the cocaine-positive individuals was higher than in controls and had a significant inverse correlation with prostacyclin metabolite excretion. Umbilical arterial velocimetry was similar in the two groups. CONCLUSION: Recent cocaine ingestion in pregnant women decreases production of prostacyclin and negatively affects the pulsatility index of the uterine artery.

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.

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.

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.

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.

Acquired factor VIII inhibitor in a patient with chronic myelogenous leukemia receiving interferon-alfa therapy.

OBJECTIVE: To report a case of an acquired factor VIII inhibitor associated with the use of interferon-alfa. CASE SUMMARY: A 58-year-old white man with newly diagnosed chronic myelogenous leukemia (CML) was initially treated with hydroxyurea. Interferon-alfa therapy was started six weeks later in order to enhance the response, with gradual reduction and eventual discontinuation of hydroxyurea. Interferon-alfa was continued for one year. Following bone marrow aspiration at one year, the patient developed significant bleeding and bruising at the site of extraction. His hemoglobin decreased from 11.3 to 9.3 g/dL and his activated partial thromboplastin time was elevated at 72 seconds. The factor VIII concentration was 0.02 units/mL; factor VIII inhibitor concentration was 58 Bethesda units. A diagnosis of an acquired factor VIII inhibitor was made, and the patient was treated with activated factor VII concentrates and prednisone. Interferon-alfa was discontinued, and the inhibitor subsequently disappeared over the next six weeks. The patient did not have any further bleeding problems. DISCUSSION: Acquired factor VIII inhibitors other than in patients with hemophilia are rare. To date, there are no reported cases of factor VIII inhibitors associated with CML. Moreover, the temporal association with interferon-alfa administration suggests a causal relationship. There are only two previous case reports suggesting interferon-alfa as a cause of factor VIII inhibitors. CONCLUSIONS: Induction of factor VIII inhibitors is a serious potential complication of therapy with interferon-alfa. We suggest that a diagnosis of an acquired factor VIII inhibitor be considered in patients who experience unexplained bleeding with interferon-alfa therapy.

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.

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.

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.

The utility and prediction of allogeneic blood transfusion use in orthopedic surgery.

It is possible to predict the likelihood of postoperative blood transfusion using patient variables. The information could be used to target the high-risk group for intervention(s) that would subsequently reduce the risk of exposure to allogeneic blood. The cost of several of the alternatives to allogeneic blood precludes their use on all surgical patients, and hence the need to identify those patients who are most likely to benefit from such therapy. Further research is needed to assess the impact of predictive models on the use of allogeneic blood and costs. Research is also needed to clarify the impact of blood transfusion on perioperative morbidity and mortality, in patients with and without heart disease. If such an association does indeed exist, then an optimal hemoglobin or transfusion threshold is needed to guide clinicians in caring for their patients.

Calculation vs calibration curve for INR determination. Results of an interlaboratory proficiency scheme.

We surveyed 271 laboratories participating in a quality assessment program to ascertain whether the use of a calibration curve for determining the international normalized ratio (INR) would improve interlaboratory accuracy and precision. Lyophilized warfarinized samples with INR values assigned through manual calibration against internationally assigned rabbit reference thromboplasts were assayed for prothrombin time. Calibration analysis on the results was performed by linear regression. In all but 1 sample, the mean INR value computed by the calibration method was closer to the "true" value than the mean for the conventional calculation method using the International Sensitivity Index (ISI); the ISI calculation consistently overestimated the true value. Interlaboratory variation decreased using the calibration method. Variation from reagent to reagent was greater than from instrument to instrument, but was reduced by the calibration method. The specificity of the ISI for instrument type did not seem to alter the findings. Use of in-house calibrators to verify the ISI improved precision but not necessarily accuracy. The formation of a stable calibration line is consistent over time, but further studies are required to confirm whether such calibration improves the accuracy and precision of INR determination in practice.

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.

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.

Prospective validation of a point score system for predicting blood transfusion following hip or knee replacement.

BACKGROUND: The purpose of this study was to validate a previously published point score system for predicting the likelihood of a postoperative blood transfusion following hip or knee replacement. STUDY DESIGN AND METHODS: Data were collected prospectively on 460 sequential patients undergoing elective hip and knee replacement at two academic hospitals. Blood transfusion frequency was determined for patients in each of the four risk strata, as defined by the point score system. The accuracy of the system was validated by calculating the area under the receiver operating characteristic (ROC) curve for each site. Data were then combined and inappropriate blood transfusions were eliminated, by using the American College of Physicians guidelines. The frequencies of blood transfusion within each strata were recalculated along with an ROC curve. RESULTS: The point score system accurately predicted the likelihood of blood transfusion at both hospitals, despite marked differences in overall transfusion frequencies. The calculated areas under the ROC curves were 0.78 and 0.79 for the two sites. The point score system also proved valid when only appropriate blood transfusions were considered, with a calculated area under the ROC curve of 0.74. CONCLUSION: The point score system can accurately predict the likelihood of postoperative blood transfusion following hip or knee replacement. Such a system can be used to target high-risk patients for preoperative autologous blood donation.

Body weight does not predict for anti-Xa levels after fixed dose prophylaxis with enoxaparin after orthopedic surgery.

Enoxaparin after joint arthroplasty is effective prophylaxis against venous thromboembolism. This is usually given as a fixed dose without monitoring of anti-Xa levels. This study assesses the relationship between trough anti-Xa levels, body weight, and venous thromboembolism. Consenting patients at three institutions were treated with Enoxaparin 30 mg subcutaneously bis in die postoperatively until discharge. Chromogenic anti-Xa levels were measured on the fifth postoperative day by the method of Stachrome (Diagnostica Stago). All patients had bilateral compression doppler ultrasonography on day 10 or discharge and were followed for 12 weeks for evidence of venous thromboembolism. Eleven patients developed objectively confirmed venous thromboembolism during the study. In this study, there was poor correlation between weight and anti-Xa levels. In addition, body weight and anti-Xa levels of patients who developed venous thromboembolism were compared to those who did not and there were no significant differences between the two groups. In conclusion, this study shows that there is poor correlation of trough anti-Xa levels with body weight. Recognizing the low overall event rate this study does not support the need to monitor anti-Xa levels or adjusting the dose according to weight.

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.

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.

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.

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.