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Objectives: To compare neonatal morbidity in late preterm pregnancies with small-for-gestational-age fetuses, between those exposed and not exposed to antenatal corticosteroids (ACS)., Methods: A retrospective study which included growth-restricted fetuses delivered at gestational week 34+0 to 36+6 weeks at a tertiary university-affiliated hospital, from March 2016 to March 2022. The primary composite outcome included the need for oxygen therapy or ventilation, respiratory distress syndrome, transient tachypnea of the newborn, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage grade III/IV and neonatal mortality., Results: The primary composite outcome was comparable between those who did and did not receive ACS (26.1 vs. 20.8 %, p=0.512). Neonatal morbidity rates did not differ significantly between the groups, except for hypoglycemia, which was more common among neonates from ACS-exposed mothers (37.0 vs. 19.5 %, p=0.037). Multivariate analysis, adjusted for gestational diabetes and the mode of delivery showed no significant difference in the composite outcome between the groups (OR=2.03, 95 % CI 0.79-5.20, p=0.142). Cesarean delivery was associated with a higher risk of the primary outcome (OR=2.13, 95 % CI 1.17-3.85, p=0.013). After excluding those who did not receive the initial betamethasone dose within 2-7 days before delivery, the primary composite outcome remained similar between the groups. The primary composite outcome was similar among severely growth-restricted fetuses (<5th percentile) exposed and not exposed to ACS (29.2 vs. 22.0 %, p=0.560)., Conclusions: Among preterm pregnancies complicated by small-for-gestational-age fetuses, ACS did not lower the rate of neonatal morbidity., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

Purpose: To examine maternal, obstetrical, and neonatal outcomes of pregnancies complicated by major fetal anomalies., Methods: A 10 year retrospective cohort study at a tertiary university hospital compared maternal and obstetrical outcomes between women with singleton pregnancies complicated by major fetal anomalies, and a control group with non-anomalous fetuses., Results: For the study compared to the control group, the median gestational age at delivery was lower: 37.0 vs. 39.4 weeks (p < 0.001); and the preterm delivery rates were higher, both at < 37 weeks (46.2 vs. 6.2%, p < 0.001) and < 32 weeks (15.4 vs. 1.2%, p < 0.001). For the study compared to the control group, the placental abruption rate was higher (6.8 vs. 0.9%, p = 0.002); 87.5 vs. 100% occurred before labor. For the respective groups, the mean gestational ages at abruption were 32.8 ± 1.3 and 39.9 ± 1.7 weeks (p = 0.024); and cesarean section and postpartum hemorrhage rates were: 53.8 vs. 28.3% (p < 0.001) and 11.3 vs. 2.8% (p = 0.001), respectively. For the respective groups, hypertensive disorders of pregnancy rates were 9.5 vs. 2.1% (p = 0.004), stillbirth rates were 17.1 vs. 0.3% (p < 0.001), and neonatal death rates 12.5 vs. 0.0% (p < 0.001). Major fetal anomalies were found to be associated with adverse maternal outcomes (OR = 2.47, 95% CI 1.50-4.09, p < 0.001). Polyhydramnios was identified as an independent risk factor in a multivariate analysis that adjusted for fetal anomalies, conception by IVF, and primiparity for adverse maternal outcomes (OR = 4.7, 95% CI 1.7-13.6, p < 0.001)., Conclusions: Pregnancies with major fetal anomalies should be treated as high-risk due to the increased likelihood of adverse maternal and neonatal outcomes., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To examine the accuracy of sonographic fetal weight to predict birthweight in very preterm infants (<32 weeks), and to compare the accuracy of estimated fetal weight (EFW) between those small for gestational age (SGA) and those appropriate for gestational age (AGA)., Study Design: A retrospective study was conducted of data recorded between January 2010 and March 2023. Included were women with singleton livebirths at 23+0-31+6 weeks who had an EFW within one week from delivery. Mean percentage error, mean absolute percentage error, and underestimation and overestimation rates were calculated. We compared the accuracy of EFW between SGA and AGA infants., Results: In total, 360 women were included. The mean absolute percentage error was 7.8 % (range 0 %-68.9 %); for 207 (57.5 %) infants the percentage error was within ±10 %. Overestimation error >10 % was observed in 102 (28.3 %) infants and errors >20 % in 34 (9.4 %). Among infants born in the periviable period (23+0 - 25+6 weeks; N = 56), the mean absolute percentage error was 9.8 % (range: 0 %-40.3 %); the value was within ±10 % for only 28 periviable infants (50 %) and exceeded 20 % for 16.1 %. Among SGA compared to AGA infants, the mean absolute percentage error was higher (11.1% vs. 6.6 %, p = 0.035). Overestimation error >10 % was more frequent among SGA than AGA infants (55 (49.1 %) vs. 47 (19.0 %), p < 0.001). In a multivariate logistic regression analysis, SGA status was independently associated with a higher mean percentage error (beta = 0.260, p < 0.001) and an increased risk of an error >10 % (odds ratio = 2.1, 95 % confidence interval 1.2-3.5, p = 0.008)., Conclusions: Sonographic EFW is limited in assessing very preterm infants, particularly those who are SGA or born during the periviable period. These limitations should be considered regarding impending very preterm births and concerns about abnormal fetal growth., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest related to this work, (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Objective:  Our objective was to examine the association between sonographic estimated fetal weight (EFW) and obstetrical and neonatal outcomes in women with neonatal macrosomia., Study Design:  This study, conducted at a tertiary university-affiliated hospital from 2017 to 2021, compared obstetrical and neonatal outcomes between two groups of women who delivered macrosomic newborns (actual birth weight ≥ 4,000 g): (1) those with EFW ≥ 3,800 g (suspected impending macrosomia) and (2) those with EFW < 3,800 g (unsuspected impending macrosomia)., Results:  During the study period, 854 women with neonatal macrosomia attempted vaginal delivery. Only 9.2% had a sonographic EFW ≥ 4,000 g. Among women with EFW ≥3,800 g ( n  = 317) compared with EFW < 3,800 g ( n  = 537), the cesarean delivery (CD) rate was higher (17.0 vs. 10.5%, p  = 0.004) and the operative delivery rate was lower (3.2 vs. 0.6%, p  = 0.015). Among primiparous women, the CD rate was higher among those with EFW ≥ 3,800 versus <3,800 g (37.3 vs. 23.2%, p  = 0.033). EFW ≥3,800 g was associated with CD, regardless of predelivery body mass index, parity, diabetes mellitus, maximal fetal weight at previous deliveries, actual birth weight, and labor induction ( p  = 0.014). EFW ≥3,800 g and diabetes mellitus were independent predictors of CD. Among women with EFW ≥3,800 g and diabetes mellitus, the risk of CD was double that of those without diabetes and with EFW ≥ 3,800 g (31.4% vs. 15.2%, p  = 0.02), although their actual birth weights were similar. Obstetrical and neonatal outcomes were similar between those with sonographic EFW ≥3,800 and < 3,800 g., Conclusion:  Larger EFW increased CD risk among pregnancies with actual neonatal macrosomia. Antenatally suspected macrosomia might alter labor management due to concerns for potential complications, especially when associated with primiparity, diabetes mellitus, or maternal obesity. The increase in the CD rate did not show an association with improved maternal and neonatal outcomes., Key Points: · Antenatally suspected macrosomia might alter labor management due to concerns about complications.. · Larger EFW increased cesarean delivery risk among pregnancies with actual neonatal macrosomia.. · The increase in the cesarean delivery rate was not associated with improved outcomes.., Competing Interests: None declared., (Thieme. All rights reserved.)

Objectives : As the COVID-19 pandemic wanes, understanding maternal-fetal antibody transfer remains crucial for optimizing vaccination strategies. This study evaluates anti-SARS-CoV-2 antibody levels in amniotic fluid following maternal BNT162b2 mRNA vaccination and/or COVID-19 infection during early pregnancy, focusing on the first and second trimesters. Methods : A retrospective cohort study was conducted at a tertiary university-affiliated hospital, involving 149 pregnant women who underwent amniocentesis. Anti-SARS-CoV-2 spike IgG levels were measured in amniotic fluid samples. Participants were categorized based on vaccination and infection status: vaccine-only, infection-only, vaccine + infection, and no vaccine/infection. Correlations between antibody levels and the time since vaccination or infection were analyzed. Results : The vaccine + infection group had a higher proportion of positive antibody levels compared to the vaccine-only group (63.6% vs. 35.9%, p = 0.029). Median SARS-CoV-2 IgG levels were significantly higher in the vaccine + infection group (283.0 AU/mL) than in the vaccine-only group (64.1 AU/mL, p = 0.006). Women who received three vaccine doses had higher antibody levels and more positive antibody rates compared to those with one or two doses. A significant negative correlation was found between antibody levels and the interval since the last vaccine dose or infection. Conclusions : Our results indicate the presence of anti-SARS-CoV-2 antibodies in the amniotic fluid, reflecting antibody transfer during early pregnancy. However, a noticeable decrease in immunity was observed, as indicated by declining amniotic fluid antibody levels over time. Further studies are needed to determine the optimal timing and number of boosters required to protect against new variants of SARS-CoV-2.

Purpose: To assess a possible association between marked proteinuria and the risk of preeclampsia with severe features, as defined by the American College of Obstetricians and Gynecologists., Methods: This retrospective study included data recorded at a tertiary university-affiliated hospital between 2017 and 2022. Women at or beyond 24 weeks of gestation with proteinuria (protein levels > 300 mg in a 24 h urine collection) and normal blood pressure during the initial 48 h of admission were included. Obstetrical and neonatal outcomes were compared between women with mild proteinuria (300-1000 mg/24 h) and marked proteinuria (≥ 1000 mg/24 h)., Results: Among the women with marked proteinuria (n = 48) compared to those with mild proteinuria (n = 108), the incidences were higher of preeclampsia (50.0% vs. 22.2%, p = 0.001) and of preeclampsia with severe features (18.8% vs. 2.8%, p < 0.001). In multivariate analysis that adjusted for maternal age, primiparity, multiple pregnancy, uric acid level > 6 mg/dL and aspirin treatment, marked proteinuria was a risk factor for preeclampsia with severe features (adjusted odds ratio [aOR] = 10.2, confidence interval [CI] 95% 1.9-54.0, p = 0.007) and for small-for-gestational-age infants (aOR = 2.4, 95% CI 1.02-5.6, p = 0.001). Among women with marked compared to mild proteinuria, rates were also higher of labor induction (58.3% vs. 25.9%, p < 0.001), indicated preterm delivery (41.7% vs. 25.0%, p = 0.04) and admission to the neonatal intensive care unit (44.1% vs. 25.8%, p = 0.017)., Conclusions: Women with marked compared to mild isolated proteinuria showed higher risk of developing preeclampsia with severe features and of delivering small-for-gestational-age neonates., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Evidence is inconsistent regarding the impact of late gestational diabetes mellitus (GDM) on perinatal outcomes., Objectives: To evaluate associations of GDM diagnosed in the third trimester (late GDM) with adverse obstetric and neonatal outcomes., Search Strategy: We searched Embase, Medline, and Web of Science from January 1, 1990 to June 16, 2022, for observational studies., Selection Criteria: Late GDM was defined as a de novo diagnosis, i.e. after a negative screening for diabetes in the second trimester, and at later than 28 weeks of pregnancy., Data Collection and Analysis: Each abstract and full-text article was independently reviewed by the same two authors. Quality was assessed with the use of the Newcastle-Ottawa Scale. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model., Main Results: Twelve studies were identified as meeting the inclusion criteria, including 3103 patients (571 with late GDM and 3103 controls). Incidences of shoulder dystocia (OR 1.57, 95% CI 1.02-2.42, P = 0.040), 5-minute Apgar score <7 (OR 1.80, 95% CI 1.14-2.86, P = 0.024), cesarean delivery (OR 1.98, 95% CI 1.51-2.60, P < 0.001), and emergent cesarean delivery (OR 1.57, 95% CI 1.02-2.40, P = 0.040) were significantly higher among women with late GDM than among the controls. The groups showed similarity in the rates of fetal macrosomia, large-for-gestational-age fetuses, neonatal hypoglycemia, and hypertensive disorders of pregnancy., Conclusions: This meta-analysis showed associations of late GDM with increased adverse perinatal outcomes. Prospective studies should evaluate the impact on perinatal outcomes of repeated third-trimester screening for late GDM., (© 2023 International Federation of Gynecology and Obstetrics.)

The 2023 Supreme Court Decision from Students for Fair Admissions v. Harvard and Students for Fair Admissions v. University of North Carolina threatens the current progress in achieving diversity within undergraduate and graduate medical education. This is necessary to achieve a diverse healthcare workforce, which is a key to healing historical healthcare trauma, eliminating health disparities, and providing equitable healthcare access for all communities. Although the Supreme Court decision seems obstructionist, viable opportunities exist to enhance recruitment further and solidify diversity efforts in undergraduate and graduate medical education to achieve these goals., (© 2024. W. Montague Cobb-NMA Health Institute.)

Objectives: To examine the prevalence and risk factors of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) colonization among women who delivered preterm and at term., Methods: A prospective observational study of maternal ESBL-E rectovaginal colonization in threatened preterm labor and low-risk term pregnancies was conducted between March 2017 and August 2021 at the Galilee Medical Center, Israel. Obstetric and neonatal complications were compared between colonized and non-colonized mothers and neonates., Results: ESBL-E colonization was similar in the preterm (n = 202) and term (n = 172) groups: 14.4% and 16.9%, respectively (P = 0.567). The maternal-neonatal transmission rate was higher in the preterm than the term group but the difference was not statistically significant: 42.1% and 22.2%, respectively (P = 0.42). Prematurity was a risk factor of neonatal ESBL-E colonization (odds ratio 1.33, 95% confidence interval 1.01-1.75, P = 0.041). ESBL-E-colonized preterm infants were delivered at an earlier gestational age and were more likely to have complications. Maternal ESBL-E colonization and transmission were more prevalent in pregnancies complicated by threatened preterm labor or premature rupture of membranes than in term pregnancies., Conclusions: These findings emphasize the need for further research on the cost-effectiveness of screening for maternal ESBL-E colonization in preterm labor, to prevent neonatal infectious complications., Clinicaltrials: gov identifier NCT03251885., (© 2022 International Federation of Gynecology and Obstetrics.)

Background: Prophylactic antibiotic use in preterm premature rupture of membranes is associated with significantly reduced intra-amniotic infection and improved neonatal outcome, although data are insufficient to determine the optimal antibiotic regimen. Ampicillin resistance has changed the epidemiology of neonatal sepsis., Objective: This study aimed to determine the efficacy of two antibiotic regimens in prolonging the latency period in women with preterm premature rupture of membranes., Study Design: This randomized-controlled trial was conducted in 3 tertiary university-affiliated hospitals. A total of 124 women with preterm premature rupture of membranes at <37 weeks of gestation were randomized into two antibiotic prophylactic protocols: ampicillin + roxithromycin and cefuroxime + roxithromycin. The latency period length, neonatal adverse outcomes, and maternal infectious morbidity, including intrauterine infection, intrapartum fever, postpartum antibiotic treatment, endometritis, and wound infection, were measured and compared., Results: Maternal infectious morbidity was higher in the ampicillin group than in the cefuroxime group (17.7% vs 6.5%; 1-sided P value =.048). The pathogen distribution among placenta, membrane, cord, and uterine cultures differed between the groups (P=.017). Enterobacteriaceae spp. cultures were identified in 68.6% of the cultures in the ampicillin group and 43.2% in the cefuroxime group (P=.036). The composite neonatal adverse outcome was higher in the ampicillin group than in the cefuroxime group (55 [88.7%] vs 46 [74.2%]; 1-sided P value =.03). The proportion of primiparas with a latency period >4 days was significantly higher in the cefuroxime group than in the ampicillin group (odds ratio, 3.69; 95% confidence interval, 1.175-11.607; P=.025)., Conclusion: In combination with roxithromycin, the use of cefuroxime, as a prophylactic in women with premature rupture of membranes at <37 weeks of gestation, showed longer pregnancy in primiparas and less maternal and neonatal morbidity than the use of ampicillin. Further larger studies are needed to support our results., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Aim: We investigated associations of maternal obesity with late gestational diabetes mellitus (GDM) diagnosis (>34 weeks) in women with previous normal glucose screening, and associations of late GDM with obstetrical outcomes., Methods: This retrospective cohort study assessed obstetrical and neonatal outcomes of 238 women with normal (24-28 week) glucose screening results, who underwent late repeat oral glucose tolerance tests (OGTT) (>34 weeks) due to a suspected LGA fetus (54.6%) or polyhydramnios (45.4%). A sub-analysis was performed of outcomes of women with late versus mid-trimester GDM., Results: The GDM rate in repeat OGTT screening was 22.2% for the total sample, and 33% among women with morbid obesity. Among women with late GDM versus without late GDM, rates were higher for macrosomia, large-for-gestational-age fetus induction of labor, neonatal hypoglycemia, jaundice, and the need for phototherapy. Among women with late GDM, a higher pregestational BMI was associated with adverse maternal and perinatal outcomes. Higher risks for macrosomia and CS due to macrosomia were demonstrated in women with late vs. mid-trimester GDM., Conclusion: Late screening in pregnancy may reveal GDM among women with previous normal glucose screening, particularly among those with late third trimester BMI ≥ 35 kg/m 2 , GDM in a previous pregnancy or fasting glucose >95 mg/dl. Women diagnosed with GDM at >34 weeks following normal glucose screening at 24-28 weeks are at higher risk for adverse perinatal outcomes. For women with morbid obesity, or suspected macrosomia or polyhydramnios in the late third trimester, and normal glucose screening in the second trimester, retesting should be considered., (© 2022 Japan Society of Obstetrics and Gynecology.)

A novel low volume blood loop model (Ension Triad System [ETS]) incorporating pulsatile flow and a proprietary low-activation blood-contacting surface (Ension bioactive surface [EBS]) enabling high signal-to-noise performance is described. The ETS system incorporates a test chamber that allows direct comparison of material samples or finished medical devices such as catheters with varying compositions and/or surface treatments. ETS performance is presented from two independent organizations (Medtronic and MLM Labs) and includes results for hemolysis (pfHgb), platelet count, platelet activation (βTG), coagulation (TAT), inflammation (PMN Elastase, PMN CD112b, and monocyte CD112b) and immune response (SC5b-9) were made on: (1) the EBS-treated system itself without a test material (No Material, NM); (2) the EBS-treated system with an idealized untreated catheter (UC); and (3) the EBS-treated system with the prototype catheter treated with the EBS surface treatment (CC). The untreated catheter (UC) was associated with significant elevation of all activation marker levels (pfHgb excluded). The EBS-treated catheter, in direct comparison to the UC and NM catheters, appeared invisible with respect to the activation markers (all markers statistically different than the UC and equivalent to the NM control). Based on these data, we conclude that using a relatively small surface area test sample and a small volume of fresh human blood, the high signal-to-noise performance of the ETS system demonstrates comprehensive and statistically significant material differences in the major ISO 10993-4 categories of blood interaction. These data underscore the important benefit of minimal confounding of test/device responses with non-test-material/model-related responses. ETS offers a practical alternative to the common one-test-category-at-a-time approach when assessing blood/medical device interactions., (© 2022 Wiley Periodicals LLC.)

Objective: Administering prophylactic antibiotics before cesarean section (CS) decreases postpartum infections significantly. They should be administered within 60 min prior to CS. In 2014 the Israeli Ministry of Health introduced the administration of pre-operative antibiotic prophylaxis for CS as a quality criterion. This was immediately adopted by the Galilee Medical Center (GMC). This study aimed to examine the compliance to this quality standard in the GMC under 3 criteria: the type of antibiotics, timing of administration, and use of one dose only., Study Design: Data of women who underwent CS from the day of introducing the new quality standard on January 1, 2014, to July 31, 2015, were retrospectively analyzed., Results: The study included 1790 women who delivered by elective (24.4%) or emergency CS. In general, the medical staff's compliance to this quality standard was 90.9; 95.6% of the patients received the correct antibiotic, 94.6% had it within 65 min before surgery to 5 min after it, and 100% received it in less than 24 h. There was an increase in the overall compliance rate with time (logistic regression, p  = .001). During the day shift, 60.4% of CS were emergency surgeries while during the on-call shift (evening and night) almost all (99%) of the CS were emergencies ( p  < .001, 2-sided). In morning shift's emergency CS, only 4.1% of the cases were not given prophylactic antibiotics as against 7.8% in the on-call shift ( p  = .005)., Conclusion: Over a period of 18 months, the compliance to the new quality standard of administering prophylactic antibiotics before CS was 90.9%. It was particularly high in the subgroup of elective CS during the morning shift. This high compliance rate may be attributed to the introduction of clear guidelines and assignment of a specific team member, the anesthesiologist, to administer the medication.Key pointsCompliance rate to the guideline was 90.9%.Compliance was better in the morning shift.Compliance was better for elective cesarean section.Compliance was not affected by time.

Objectives: Intrahepatic cholestasis of pregnancy (ICP) is charachterized by pruritis and elevated serum bile acids (BA) and is associated with adverse obstetrical outcomes. ICP etiology is poorly understood and its incidence varies with ethnicity and geographical distribution., Objectives: Explore the prevalence and characteristics of ICP in the different Northern Israeli ethnic groups and compare maternal and perinatal outcomes according to disease severity., Material and Methods: Single-center retrospective study. Women who were diagnosed with ICP based on clinical presentation and elevated fasting BA (≥ 10 μmol/L) were included. Disease incidence, maternal and neonatal complications were explored according to ethnic subgroups analysis and obstetrical complications were examined according to disease severity., Results: The incidence of ICP in the study population was 0.58%. Higher ICP incidence was found in our cohort compared with other reports arising from Central Israel (p < 0.001). The Christian patients had a higher incidence of ICP (1.1%) and preeclampsia (23.1%). A higher rate of neonatal intensive care unit (NICU) admissions was found in the Arab Muslim and Christian groups compared with the Jewish and Druze groups (p = 0.007). A higher rate of preeclampsia was found in the severe (BA ≥ 40 μmol/L) ICP group (p < 0.001). Patients in the severe ICP group had earlier gestational age at delivery (37 versus 38.14 weeks, p < 0.001). Birth weight was significantly lower in the severe ICP group (p = 0.018)., Conclusions: The incidence of ICP at our institution was 0.58%, which is higher compared with previous reported Israeli incidence. Higher ICP and preeclampsia incidence were found among Arab Christian patients.

The physiological pattern of hormonal and signaling molecules associated with labor induction is not fully clear. We conducted a preliminary study in order to investigate hormonal changes during labor induction in women with previous cesarean section. Eighty-seven women at term, with previous cesarean section, were randomized to undergo induction of labor by breast stimulation or intracervical balloon and compared with spontaneous labor (controls). Maternal serum levels of oxytocin, prostaglandin F2α, prostaglandin E2, prolactin, estradiol, and cortisol were analyzed at 0, 3, and 6 h post-induction initiation. Fetal umbilical cord hormones were measured. No significant difference was found in the induction-to-delivery time or mode of delivery between the induction groups. Maternal serum oxytocin levels decreased to a lesser extent in the breast stimulation group vs. the control group (p=0.003, p<0.001). In the breast stimulation and control groups, prostaglandin E 2 levels increased as labor progressed (p=0.005, 0.002, respectively). Prostaglandin F2α levels decreased over time in the balloon group (p=0.039), but increased in the control group (p=0.037). Both induction methods had similar outcomes. The hormonal studies ascertained the hypothesized mechanisms, with oxytocin level higher during breast stimulation and lower in balloon induction. These observations could help clinicians determine the appropriate method for cervical ripening in women with previous cesarean section. Larger future studies are needed to examine the effect of these hormonal trends on the rate of successful labor induction and complications, such as uterine rupture, in women with previous uterine scars. ClinicalTrials.gov Identifier NCT04244747., (© 2021. Society for Reproductive Investigation.)

Device manufacturers and regulatory agencies currently utilize expensive and often inconclusive in vivo vascular implant models to assess implant material thrombogenicity. We report an in vitro thrombogenicity assessment methodology where test materials (polyethylene, Elasthane™ 80A polyurethane, Pebax®), alongside positive (borosilicate glass) and negative (no material) controls, were exposed to fresh human blood, with attention to common blood-contact use conditions and the variables: material (M), material surface modification (SM) with heparin, model (Mo), time (T), blood donor (D), exposure ratio (ER; cm 2 material/ml blood), heparin anticoagulation (H), and blood draw/fill technique (DT). Two models were used: (1) a gentle-agitation test tube model and (2) a pulsatile flow closed-loop model. Thrombogenicity measurements included thrombin generation (thrombin-antithrombin complex [TAT] and human prothrombin fragment F1.2), platelet activation (β-thromboglobulin), and platelet counts. We report that: (a) thrombogenicity was strongly dependent (p < .0001) on M, H, and T, and variably dependent (p < .0001 - > .05) on Mo, SM, and D (b) differences between positive control, test, and negative control materials became less pronounced as H increased from 0.6 to 2.0 U/ml, and (c) in vitro-to-in vivo case comparisons showed consistency in thrombogenicity rankings on materials classified to be of low, moderate, and high concern. In vitro methods using fresh human blood are therefore scientifically sound and cost effective compared to in vivo methods for screening intravascular materials and devices for thrombogenicity., (© 2020 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals LLC.)

Background: The Pipeline Vantage Embolization Device with Shield Technology is a next generation flow diverter developed to improve aneurysm occlusion and implant endothelialization in addition to lowering thrombogenicity. We report here the in vivo biocompatibility and in vitro hemocompatibility performance of the Pipeline Vantage Embolization Device with Shield Technology (Vantage) compared with the Pipeline Flex Embolization Device (Flex)., Methods: Biocompatibility (via histology), aneurysm occlusion and vessel patency (via angiography), and endothelial coverage (via scanning electron microscopy (SEM)) for the Vantage and Flex devices were assessed in the rabbit elastase aneurysm model at 90 days (n=29) and 180 days (n=27). In vitro thrombogenicity for Flex and Vantage (n=16) was assessed using a human blood flow loop model at low heparin concentration (0.6 U/mL) with thrombin generation, platelet activation and thrombus visualization as outputs., Results: Raymond Roy Occlusion Classification grade 1 was higher for Vantage (61%) compared with Flex (46%), but was not statistically significant (p>0.05). All branch vessels were patent. Histological measures for both devices were similar (p>0.05). Endothelial coverage of the implant was significantly better for Vantage compared with Flex (p<0.05). In vitro measurements of thrombin generation (thrombin-antithrombin complex (µg/mL): Vantage 0.49±0.45; Flex 10.57±9.84) and platelet activation (β-thromboglobulin (IU/µl): Vantage 0.41±0.19; Flex 4.14±2.38) were both statistically lower (p < 0.05) for Vantage compared with Flex. High resolution microscopy showed less accumulation of thrombus on Vantage as compared with Flex., Conclusion: Vantage improved aneurysm occlusion and implant endothelialization and had significantly lower thrombogenicity as compared with Flex, while preserving the biocompatibility safety profile of Flex., Competing Interests: Competing interests: RMS and JT are employees of University of Miami. AP, RJ, GG, JMW, MFW, AC are employees of Medtronic. RMS research is supported by the NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and by the National Institute of Health (R01NS111119-01A1) and (UL1TR002736, KL2TR002737) through the Miami Clinical and Translational Science Institute, from the National Center for Advancing Translational Sciences and the National Institute on Minority Health and Health Disparities. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. RMS has consulting and teaching agreements with Penumbra, Abbott, Medtronic, InNeuroCo and Cerenovus., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To characterize the prevalence of exchange transfusion (ET), clinical characteristics of infants receiving ET, and ET-associated morbidity and mortality., Study Design: We conducted a multicenter cohort study of infants ≥23 weeks of gestational age (GA) with hyperbilirubinemia who underwent ET within 30 days of birth from 1997 to 2016. We examined clinical characteristics and adverse events after ET. We used multivariable logistic regression to examine the association between clinical risk factors and death., Result: A total of 1252 infants were included; 4% died within 7 days of ET and 6% died before discharge. Compared with infants ≥37 weeks of GA, infants ≤29 weeks of GA had greater odds of death (adjusted odds ratio [95% confidence interval] = 20.08 [7.32, 55.07])., Conclusions: Infants ≤ 29 weeks of GA had greater odds of death following ET compared with term infants. These data will support clinicians in evaluating risks and prognosis for infants who require ET.

Objectives: Prophylactic antibiotic use in preterm pre-labor rupture of membranes (PPROM) is associated with a significant reduction in intra-amniotic infection and improved neonatal outcome. However, data is insufficient to determine the optimal antibiotic regimen. Considering the rise in Escherichia coli and Klebsiella pneumonia early-onset sepsis rate and the emergence of ampicillin resistance, our aim is to compare the efficiency of two antibiotic regimens in prolonging pregnancy and reducing infectious morbidity., Design: This multicenter randomized unblinded controlled prospective trial compared two antibiotic prophylactic protocols in PPROM: ampicillin + roxithromycin vs. cefuroxime + roxithromycin in 84 women with PPROM, from 12/2015-12/2019., Results: The median latency period was significantly longer (p = 0.039) in the cefuroxime + roxithromycin group (4.63 [0.59-50.18] days) than in the ampicillin + roxithromycin group (2.3 [0.15-58.3] days). Neonatal admission to neonatal intensive care unit rate, hospitalization length, neonatal respiratory distress syndrome, neonatal fever, and need for respiratory support or mechanical ventilation, were similar between the groups. K. pneumonia cultures were significantly more frequent in the ampicillin + roxithromycin group. None of the cultures were group B Streptococcus positive., Conclusions: To prolong latency period and reduce gram-negative early-onset sepsis, cefuroxime + roxithromycin is recommended as the first-line protocol in PPROM., Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02819570., (Copyright © 2020. Published by Elsevier Ltd.)

Objectives: Cesarean sections, particularly non-elective cesareans, are an important risk factor for the development of postpartum endometritis, a leading cause of postpartum febrile morbidity. We evaluated the yield of obtaining routine intrauterine culture during elective and non-elective cesarean sections, in the prevention and management of postpartum endometritis., Study Design: A retrospective comparative study investigating the distribution of uterine cultures obtained immediately after fetus and placenta delivery during cesarean sections performed in a single tertiary hospital during 2017. True pathogenic bacteria were included in the study analysis and considered as positive results, while other contaminant bacteria were excluded., Results: Positive uterine cultures were identified in 10.7 % (88/821) of cesarean sections, with no significant difference in prevalence between elective and non-elective cesareans. Escherichia coli (E.coli), isolated in 40.9 % of the positive cultures of all women, was the most common organism in non-elective cesareans vs. Group B Streptococcus (GBS) in elective cesareans. Higher rate of positive cultures was found in term vs. preterm cesareans (17.5 % vs 10.5 %, respectively, p-value = 0.04). E.coli was the most frequent pathogen reported in both women with intact membranes or premature rupture of membranes (46.3 % and 47.3 % respectively). Eight women (9.1 %) with positive cultures presented with postpartum fever; all had undergone non-elective cesarean section. In one-third of these cases the empirical antibiotic treatment was adjusted according to the uterine culture results and susceptibility testing results., Conclusions: Obtaining routine intrauterine cultures during non-elective cesarean sections might be useful for detecting significant pathogens and tailoring the antibiotic treatment in postpartum endometritis., Competing Interests: Declaration of Competing Interest None of the authors report any conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Women who have continuous intrapartum support are more likely to have a shorter labor and spontaneous vaginal birth, and are less likely to need intrapartum analgesia than women who receive usual care without support. We aimed to determine what women in labor and midwives regard as the optimal number of labor supporters and whether they should be present during medical interventions., Methods: A questionnaire was distributed to midwives participating in a national midwifery conference in June 2015. In addition, an anonymized questionnaire concerning the preferred number and type of supporters was distributed to laboring women at the beginning of labor and repeated post-partum in the maternity unit of a single tertiary medical center between March 2017 and January 2018., Results: Of 124 midwives from 18 hospitals throughout Israel attending the conference, 92 (74%) completed the questionnaire. Eighty-three percent of the midwives who responded felt that more than two supporters interferes with their work. Eighty percent of the midwives work in obstetrical units that allow up to two labor supporters, and 82% of them felt that one or two supporters is optimal. Similarly, of the 140 laboring women surveyed, 84% preferred one or two supporters. There was no difference in the preferred number of supporters between the maternal pre- and post-partum questionnaires. The laboring women and midwives had differing opinions regarding supporter presence during vacuum extraction and perineal suture. Sixty-four percent of the midwives preferred that the supporter not be present during vacuum extraction, and 45% of them preferred that the supporter not be present during perineal suture. In contrast, among the laboring women, 78% preferred supporter presence during vacuum extraction, 76% during perineal suture and 74% during vaginal examination. Interestingly, even among the midwives, 82% preferred that the supporter remain during vaginal examination and 84% preferred the supporter remain during medical rounds., Conclusions: Serious consideration should be given to restricting the number of labor supporters to two, as both laboring woman and midwives consider that to be the optimal number. In light of the difference of opinion regarding presence of supporters during certain medical procedures, additional surveys concerning the points of view of obstetricians and laboring women in additional hospitals should be considered before establishing a national policy.

Flow diversion is a disruptive technology for the treatment of intracranial aneurysms. However, these intraluminal devices pose a risk for thromboembolic complications despite dual antiplatelet therapy. We report the thrombogenic potential of the following flow diversion devices measured experimentally in a novel human blood in-vitro pulsatile flow loop model: Pipeline™ Flex Embolization Device (Pipeline), Pipeline™ Flex Embolization Device with Shield Technology™ (Pipeline Shield), Derivo Embolization Device (Derivo), and P64 Flow Modulation Device (P64). Thrombin generation (Mean ± SD; μg/mL) was measured as: Derivo (28 ± 11), P64 (21 ± 4.5), Pipeline (21 ± 6.2), Pipeline Shield (0.6 ± 0.1) and Negative Control (1.5 ± 1.1). Platelet activation (IU/μL) was measured as: Derivo (4.9 ± 0.7), P64 (5.2 ± 0.7), Pipeline (5.5 ± 0.4), Pipeline Shield (0.3 ± 0.1), and Negative Control (0.9 ± 0.7). We found that Pipeline Shield had significantly lower platelet activation and thrombin generation than the other devices tested ( p   <   .05 ) and this was comparable to the Negative Control (no device, p >   .05 ). High resolution scanning electron microscopy performed on the intraluminal and cross-sectional surfaces of each device showed the lowest accumulation of platelets and fibrin on Pipeline Shield relative to Derivo, P64, and Pipeline. Derivo and P64 also had higher thrombus accumulation at the flared ends. Pipeline device with Phosphorylcholine surface treatment (Pipeline Shield) could mitigate device material related thromboembolic complications.

Endovascular treatment of intracranial aneurysms with endoluminal flow diverters (single or multiple) has proven to be clinically safe and effective, but is associated with a risk of thromboembolic complications. Recently, a novel biomimetic surface modification with covalently bound phosphorylcholine (Shield Technology™) has shown to reduce the material thrombogenicity of the Pipeline flow diverter. Thrombogenicity of Pipeline Flex, Pipeline Shield, and Flow Redirection Endoluminal Device (FRED) in the presence of human blood under physiological flow conditions-in addition to relative increase in thrombogenicity with multiple devices-remains unknown and was investigated here. Thrombin generation (mean ± SD; μg/mL; thrombin-antithrombin complex or TAT) was measured as FRED (30.3 ± 2.9), Pipeline (13.9 ± 4.4), Pipeline Shield (0.4 ± 0.3), and negative control (no device; 0.1 ± 0.0). Platelet activation (mean ± SD; IU/μL; beta-thromboglobulin or βTG) was measured as FRED (148 ± 45), Pipeline (92.8 ± 41), Pipeline Shield (16.2 ± 3.5), and negative control (2.70 ± 0.16). FRED was significantly more thrombogenic than Pipeline and Pipeline Shield (p < 0.05) for TAT. Additionally, Pipeline Shield had significantly lower TAT and βTG than the other devices tested (p < 0.05) and these were comparable to the negative control (p > 0.05). TAT and βTG scaled proportionately with multiple Pipeline devices (N = 6) but was unaffected by multiple Pipeline Shield (N = 6) devices-the latter being statistically similar to negative control (p > 0.05). © 2018 The Authors. Journal Of Biomedical Materials Research Part A Published By Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3195-3202, 2018., (© 2018 The Authors. Journal of Biomedical Materials Research Part A published by Wiley Periodicals, Inc.)

Amid growing efforts to advance the replacement, reduction, and refinement of the use of animals in research, there is a growing recognition that in vitro testing of medical devices can be more effective, both in terms of cost and time, and also more reliable than in vivo testing. Although the technological landscape has evolved rapidly in support of these concepts, regulatory acceptance of alternative testing methods has not kept pace. Despite the acceptance by regulators of some in vitro tests (cytotoxicity, gene toxicity, and some hemocompatibility assays), many toxicity tests still rely on animals (irritation, sensitization, acute toxicity, reproductive/developmental toxicity), even where other industrial sectors have already abandoned them. Bringing about change will require a paradigm shift in current approaches to testing - and a concerted effort to generate better data on risks to human health from exposure to leachable chemicals from medical devices, and to boost confidence in the use of alternative methods to test devices. To help advance these ideas, stir debate about best practices, and coalesce around a roadmap forward, the JHU-Center for Alternatives to Animal Testing (CAAT) hosted a symposium believed to be the first gathering dedicated to the topic of in vitro testing of medical devices. Industry representatives, academics, and regulators in attendance presented evidence to support the unique strengths and challenges associated with the approaches currently in use as well as new methods under development, and drew next steps to push the field forward from their presentations and discussion.

There is a paucity of information on outpatient management and risk factors for hospitalization and complications in childhood nephrotic syndrome (NS). We described the management, patient adherence, and inpatient and outpatient usage of 87 pediatric NS patients diagnosed between 2006 and 2012 in the Atlanta Metropolitan Statistical Area. Multivariable analyses were performed to examine the associations between patient characteristics and disease outcome. We found that 51% of the patients were treated with two or more immunosuppressants. Approximately half of the patients were noted to be nonadherent to medications and urine protein monitoring. The majority (71%) of patients were hospitalized at least once, with a median rate of 0.5 hospitalizations per patient year. Mean hospital length of stay was 4.0 (3.8) days. Fourteen percent of patients experienced at least one serious disease complication. Black race, frequently relapsing/steroid-dependent and steroid-resistant disease, and the first year following diagnosis were associated with higher hospitalization rates. The presence of comorbidities was associated with longer hospital length of stay and increased risk of serious disease complications. Our results highlight the high morbidity and burden of NS and point to particular patient subgroups that may be at increased risk for poor outcome., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

Objectives: To quantify physical activity and grip strength in pediatric kidney transplant recipients and describe attitudes about exercise and exercise counseling given concerns about allograft injury., Study Design: This was a cross-sectional analysis of 101 kidney transplant recipients (7-21 years old) >6 months post-transplant. Patients completed the Physical Activity Questionnaire (PAQ). Grip strength was measured with a dynamometer. We asked about activity limitations and provider counseling. Univariate analysis and multiple linear regression were used to determine independent predictors of PAQ score and grip strength z score., Results: We enrolled 101 of 122 eligible patients. Median PAQ score was 2.2 (range 0-5) and was lower compared with controls (P < .001). The average grip strength z score was -1.1 and -0.7 in the right and left hand, respectively. Predictors of lower grip strength were younger age (P = .036), non-African American race (P = .029), lower height z score (P = .010), and longer percentage of lifetime with kidney disease (P = .029). Although 49% and 67% limited exercise before and after transplant, respectively, 67% reported increased activity after transplant. By parent report, provider counseling included limiting certain activities (71%) and encouraging regular exercise (45%)., Conclusion: Physical activity and grip strength are low after kidney transplant. Patients perceive an emphasis on exercise limitations rather than the benefits of regular exercise. Interventions that encourage physical activity may be beneficial., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Electronic fetal heart monitor chart speeds vary between countries, and it is unclear whether differing chart speeds affect physician tracing interpretation., Methods: Twenty-minute segments of 19 tracings were displayed on both 1 and 3 cm/min strips and interpreted by 14 physicians at the particular speed they were accustomed to reading. Interpretations of tracing characteristics were compared between groups using free margin kappa, a measure of interobserver agreement., Results: Compared to 3 cm/min tracings, 1 cm/min tracings were significantly more often identified as having absent than minimal variability, and minimal than moderate variability. Accelerations were significantly more often identified in 1 versus 3 cm/min strips. There were no significant differences between groups with respect to baseline fetal heart rate, prolonged or repetitive decelerations, or American College of Obstetricians and Gynecologists tracing category. Neither chart speed had substantial interobserver agreement in tracing variables; however, agreement was consistently higher in 3 versus 1 cm/min tracings (all p < 0.05)., Conclusions: Tracing interpretation is significantly affected by fetal monitor chart speed with regards to variability, acceleration and deceleration. Further studies are required to determine if differences in chart speed interpretation affect clinical management.

Objective: The purpose of our study was to determine whether the current antibiotic regimen for preterm premature rupture of membranes (PPROM) is adequate for covering the current causative agents and sensitivities of chorioamnionitis and early-onset neonatal sepsis., Study Design: During a 3-year period, we retrieved the results from placental and amniotic membrane cultures obtained at delivery in cases of maternal fever, chorioamnionitis, and PPROM, and from blood cultures obtained from neonates with early-onset sepsis (EOS) in three participating hospitals. Sensitivity of pathogens to antimicrobial agents was performed using routine microbiologic techniques., Results: There were 1,133 positive placental or amniotic cultures, 740 (65.3%) were from gram-negative Enterobacteriaceae. There were 27 neonates diagnosed with EOS with positive blood cultures. Aerobic Enterobacteriaceae accounted for 14 cases (52%) and group B streptococcus for 7 cases (26%). Of the Escherichia coli and Klebsiella sp., only 38% were sensitive to ampicillin., Conclusion: Local pathogens and their antibiotic sensitivity profiles should be explored every few years and an effective antibiotic protocol chosen to cover the main pathogens causing chorioamnionitis and EOS. Consideration should be made for changing ampicillin in women with PPROM to a regimen with better coverage of gram-negative Enterobacteriaceae., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Objective: Because of the known complications of fetal macrosomia, our hospital's policy has been to discuss the risks of shoulder dystocia and cesarean section (CS) in mothers with a sonographic estimated fetal weight (SEFW) ≥ 4,000 g at term. The present study was performed to determine the effect of this policy on CS rates and pregnancy outcome., Study Design: We examined the pregnancy outcomes of the macrosomic (≥ 4,000 g) neonates in two cohorts of nondiabetic low risk women at term without preexisting indications for cesarean: (1) SEFW ≥ 4,000 g (correctly suspected macrosomia) and (2) SEFW < 4,000 g (unsuspected macrosomia)., Results: There were 238 neonates in the correctly suspected group and 205 neonates in the unsuspected macrosomia group, respectively. Vaginal delivery was accomplished in 52.1% of the suspected group and 90.7% of the unsuspected group, respectively, p < 0.001. There was no difference in the rates of shoulder dystocia. The odds ratio for CS was 9.0 (95% confidence interval, 5.3-15.4) when macrosomia was correctly suspected., Conclusion: The policy of discussing the risk of macrosomia with SEFW ≥ 4,000 g to women is not justified. A higher SEFW to trigger counseling for shoulder dystocia and CS, more consistent with American College of Obstetrics and Gynecology (ACOG) guidelines, should be considered., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Tight junctions (TJs) are dynamic, multiprotein intercellular adhesive contacts that provide a vital barrier function in epithelial tissues. TJs are remodeled during physiological development and pathological mucosal inflammation, and differential expression of the claudin family of TJ proteins determines epithelial barrier properties. However, the molecular mechanisms involved in TJ remodeling are incompletely understood. Using acGFP-claudin 4 as a biosensor of TJ remodeling, we observed increased claudin 4 fluorescence recovery after photobleaching (FRAP) dynamics in response to inflammatory cytokines. Interferon γ and tumor necrosis factor α increased the proportion of mobile claudin 4 in the TJ. Up-regulation of claudin 4 protein rescued these mobility defects and cytokine-induced barrier compromise. Furthermore, claudins 2 and 4 have reciprocal effects on epithelial barrier function, exhibit differential FRAP dynamics, and compete for residency within the TJ. These findings establish a model of TJs as self-assembling systems that undergo remodeling in response to proinflammatory cytokines through a mechanism of heterotypic claudin-binding incompatibility., (© 2014 Capaldo et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)

Junctional adhesion molecule-A (JAM-A) is a tight junction-associated signaling protein that regulates epithelial cell proliferation, migration, and barrier function. JAM-A dimerization on a common cell surface (in cis) has been shown to regulate cell migration, and evidence suggests that JAM-A may form homodimers between cells (in trans). Indeed, transfection experiments revealed accumulation of JAM-A at sites between transfected cells, which was lost in cells expressing cis- or predicted trans-dimerization null mutants. Of importance, microspheres coated with JAM-A containing alanine substitutions to residues 43NNP45 (NNP-JAM-A) within the predicted trans-dimerization site did not aggregate. In contrast, beads coated with cis-null JAM-A demonstrated enhanced clustering similar to that observed with wild-type (WT) JAM-A. In addition, atomic force microscopy revealed decreased association forces in NNP-JAM-A compared with WT and cis-null JAM-A. Assessment of effects of JAM-A dimerization on cell signaling revealed that expression of trans- but not cis-null JAM-A mutants decreased Rap2 activity. Furthermore, confluent cells, which enable trans-dimerization, had enhanced Rap2 activity. Taken together, these results suggest that trans-dimerization of JAM-A occurs at a unique site and with different affinity compared with dimerization in cis. Trans-dimerization of JAM-A may thus act as a barrier-inducing molecular switch that is activated when cells become confluent., (© 2014 Monteiro et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)

Objectives: Different flow patterns and shear forces were shown to cause significantly more luminal narrowing and neointimal tissue proliferation in coronary than in infrainguinal vein grafts. As constrictive external mesh support of vein grafts led to the complete suppression of intimal hyperplasia (IH) in infrainguinal grafts, we investigated whether mesh constriction is equally effective in the coronary position., Methods: Eighteen senescent Chacma baboons (28.8 ± 3.6 kg) received aorto-coronary bypass grafts to the left anterior descending artery (LAD). Three groups of saphenous vein grafts were compared: untreated controls (CO); fibrin sealant-sprayed controls (CO + FS) and nitinol mesh-constricted grafts (ME + FS). Meshes consisted of pulse-compliant, knitted nitinol (eight needles; 50 μm wire thickness; 3.4 mm resting inner diameter, ID) spray attached to the vein grafts with FS. After 180 days of implantation, luminal dimensions and IH were analysed using post-explant angiography and macroscopic and histological image analysis., Results: At implantation, the calibre mismatch between control grafts and the LAD expressed as cross-sectional quotient (Qc) was pronounced [Qc = 0.21 ± 0.07 (CO) and 0.18 ± 0.05 (CO + FS)]. Mesh constriction resulted in a 29 ± 7% reduction of the outer diameter of the vein grafts from 5.23 ± 0.51 to 3.68 ± 0 mm, significantly reducing the calibre discrepancy to a Qc of 0.41 ± 0.17 (P < 0.02). After 6 months of implantation, explant angiography showed distinct luminal irregularities in control grafts (ID difference between widest and narrowest segment 74 ± 45%), while diameter variations were mild in mesh-constricted grafts. In all control grafts, thick neointimal tissue was present [600 ± 63 μm (CO); 627 ± 204 μm (CO + FS)] as opposed to thin, eccentric layers of 249 ± 83 μm in mesh-constricted grafts (ME + FS; P < 0.002). The total wall thickness had increased by 363 ± 39% (P < 0.00001) in CO and 312 ± 61% (P < 0.00001) in CO + FS vs 82 ± 61% in ME + FS (P < 0.007)., Conclusions: In a senescent non-human primate model for coronary artery bypass grafts, constrictive, external mesh support of saphenous veins with knitted nitinol prevented focal, irregular graft narrowing and suppressed neointimal tissue proliferation by a factor of 2.5. The lower degree of suppression of IH compared with previous infrainguinal grafts coincided with a lesser reduction of calibre mismatch in the coronary grafts.

Background: Flow patterns and shear forces in native coronary arteries are more protective against neointimal hyperplasia than those in femoral arteries. Yet, the caliber mismatch with their target arteries makes coronary artery bypass grafts more likely to encounter intimal hyperplasia than their infrainguinal counterparts due to the resultant slow flow velocity and decreased wall stress. To allow a site-specific, flow-related comparison of remodeling behavior, saphenous vein bypass grafts were simultaneously implanted in femoral and coronary positions., Methods: Saphenous vein grafts were concomitantly implanted as coronary and femoral bypass grafts using a senescent nonhuman primate model. Duplex ultrasound-based blood flow velocity profiles and vein graft and target artery dimensions were correlated with dimensional and histomorphologic graft remodeling in large, senescent Chacma baboons (n = 8; 28.1 ± 4.9 kg) during a 24-week period., Results: At implantation, the cross-sectional quotient (Q(c)) between target arteries and vein grafts was 0.62 ± 0.10 for femoral grafts vs 0.17 ± 0.06 for coronary grafts, resulting in a dimensional graft-to-artery mismatch 3.6 times higher (P < .0001) in coronary grafts. Together with different velocity profiles, these site-specific dimensional discrepancies resulted in a 57.9% ± 19.4% lower maximum flow velocity (P = .0048), 48.1% ± 23.6% lower maximal cycling wall shear stress (P = .012), and 62.2% ± 21.2% lower mean velocity (P = .007) in coronary grafts. After 24 weeks, the luminal diameter of all coronary grafts had contracted by 63%, from an inner diameter of 4.49 ± 0.60 to 1.68 ± 0.63 mm (P < .0001; subintimal diameter: -41.5%; P = .002), whereas 57% of the femoral interposition grafts had dilated by 31%, from 4.21 ± 0.25 to 5.53 ± 1.30 mm (P = .020). Neointimal tissue was 2.3 times thicker in coronary than in femoral grafts (561 ± 73 vs 240 ± 149 μm; P = .001). Overall, the luminal area of coronary grafts was an average of 4.1 times smaller than that of femoral grafts., Conclusions: Although coronary and infrainguinal bypass surgery uses saphenous veins as conduits, they undergo significantly different remodeling processes in these two anatomic positions., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Constriction of vein grafts with braided external nitinol meshes had previously led to the successful elimination of neointimal tissue formation. We investigated whether pulse compliance, smaller kink-free bending radius, and milder medial atrophy can be achieved by knitting the meshes rather than braiding, without losing the suppressive effect on intimal hyperplasia., Methods: Pulse compliance, bending stiffness, and bending radius, as well as longitudinal-radial deformation-coupling and radial compression, were compared in braided and knitted nitinol meshes. Identical to previous studies with braided mesh grafts, a senescent nonhuman primate model (Chacma baboons; bilateral femoral interposition grafts/6 months) mimicking the clinical size mismatch between vein grafts and runoff arteries was used to examine the effect of knitted external meshes on vein grafts: nitinol mesh-constricted (group 1); nitinol mesh-constricted and fibrin sealant (FS) spray-coated for mesh attachment (group 2); untreated control veins (group 3), and FS spray-coated control veins (group 4)., Results: Compared with braided meshes, knitted meshes had 3.8-times higher pulse compliance (3.43 ± 0.53 vs 0.94 ± 0.12%/100 mm Hg; P = .00002); 30-times lower bending stiffness (0.015 ± 0.002 vs 0.462 ± 0.077 Nmm(2); P = .0006); 9.2-times narrower kink-free bending radius (15.3 ± 0.4 vs 140.8 ± 22.4 mm; P = .0006), and 4.3-times lower radial narrowing caused by axial distension (18.0% ± 1.0% vs 77.0% ± 3.7%; P = .00001). Compared with mesh-supported grafts, neointimal tissue was 8.5-times thicker in group I (195 ± 45 μm) vs group III (23.0 ± 21.0 μm; P < .001) corresponding with a 14.3-times larger neointimal area in group I (4330 ± 957 × 103 μm(2)) vs group III (303 ± 221× 103 μm(2); P < .00004). FS had no significant influence. Medial muscle mass remained at 43.4% in knitted meshes vs the 28.1% previously observed in braided meshes., Conclusion: Combining the suppression of intimal hyperplasia with a more physiologic remodeling process of the media, manifold higher kink-resistance, and lower fraying than in braided meshes makes knitted nitinol an attractive concept in external vein graft protection., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

External mesh constriction of vein grafts was shown to mitigate intimal hyperplasia by lowering circumferential wall stress and increasing fluid shear stress. As under-constriction leaves vein segments unsupported and thus prone to neointimal proliferation while over-constriction may cause wall folding optimal mesh sizing holds a key to clinical success. Diameter fluctuations and the occurrence of wall folding as a consequence of external constriction with knitted Nitinol meshes were assessed in saphenous vein grafts from 100 consecutive coronary artery bypass (CABG) patients. Subsequently, mesh dimensions were identified that resulted in the lowest number of mesh sizes for all patients either guaranteeing tight continual mesh contact along the entire graft length (stipulation A) or preventing wall folding (stipulation B). A mathematical data classification analysis and a statistical single-stage partitioning approach were independently applied alternatively prioritizing stipulation A or B. Although the risk of folding linearly increased when constriction exceeded 24.6% (Chi squared test p = 0.0004) the actual incidence of folding (8.6% of veins) as well as the degree of lumenal encroachment (6.2 ± 2.1%) were low. Folds were always single, narrow longitudinal formations (height: 23.3 ± 4.0% of inner diameter/base: 16.6 ± 18.1% of luminal circumference). Both analytical methods provided an optimum number of 4 mesh sizes beyond which no further advantage was seen. While the size ranges recommended by both methods assured continual tight mesh contact with the vein the narrower range suggested by the mathematical data classification analysis (3.0-3.7 mm) put 20.6 ± 12.5% of length in 69% of veins at risk of folding as opposed to 21.3 ± 25.9% being at risk in the wider size range (3.0-4.2 mm) suggested by the statistical partitioning approach. Four mesh sizes would provide uninterrupted mesh contact in 98% of vein grafts in CABG procedures with only 26% of their length being at risk of relatively mild wall folding., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: Piperacillin-tazobactam (PIP/TAZO) has been extensively used in adults with nosocomial infections and with fever and neutropenia. The available data considering the use of PIP/TAZO have not been reviewed in detail., Objective: Review discussing the use of PIP/TAZO in neonatal and paediatric patients., Methods: Medline search focusing on articles published in English. Owing to the paucity of randomized controlled trails, uncontrolled studies and case series were included., Results/conclusion: PIP/TAZO may safely be used in paediatric patients as an empiric treatment for serious infections in hospital environments where resistance to common first-line antimicrobials has emerged. The most common indications in paediatric patients are nosocomial infections owing to resistant Gram-negatives, exacerbation of pulmonary colonization with Psuedomonas aeruginosa in patients with cystic fibrosis, intra-abdominal infections, fever and neutropenia in paediatric cancer patients. The influence of PIP/TAZO routine use on the selection of extended-spectrum beta-lactamase producing Gram-negatives and on the prevalence of vancomycin-resistant enterococci is still a matter of debate. In particular the use of PIP/TAZO in neonates and PIP/TAZO monotherapy in paediatric cancer patients with fever and neutropenia should be investigated in prospective randomized studies including a sufficient number of patients.

Medical devices, intended for blood contacting applications, undergo extensive in vitro testing followed by animal and clinical feasibility studies. Besides the use of materials known to be intrinsically blood-compatible, the surface of such devices is often modified with a coating in order to improve the performance characteristics during blood exposure. In vitro evaluation of blood-device interactions accompanies the product development cycle from the early design phase using basic material geometries until final finished-product testing. Specific test strategies can vary significantly depending on the end application, the particular study objectives and variables of interest, and cost. To examine the degree to which findings derived from two different in vitro approaches complement one another, this report contrasts findings from a simple multipass loop model with findings from a simulated cardiopulmonary bypass (CPB) model. The loop model consists of tubular test materials, with and without surface modification, formed into valved Chandler loops. The CPB model has an oxygenator with and without surface modification connected to a reservoir and a blood pump. The surface modifications studied in this report are the Carmeda BioActive Surface and Duraflo II heparin coatings. Common blood parameters in the categories of coagulation, platelets, hematology, and immunology were monitored in each model. Ideal models employ the optimal level of complexity to study the design variables of interest and to meet practical cost considerations. In the case of medical device design studies, such models should also be predictive of performance. In the more complex and realistic simulated CPB model, experimental design and cost factors prevented easy/optimum manipulation of critical variables such as blood donor (use of paired samples) and heparin level. Testing in the simpler loop model, on the other hand, readily offered manipulation of these variables, and produced findings which overlapped with observations from the more complex CPB model. Thus, the models described here complimented one another. Moreover, conclusions from consistent findings, such as favorable responses associated with the heparin coatings, between the two models were considered to be more robust.

Surfaces of medical devices made of polymeric materials may promote thrombosis and inflammation. Therefore, in an attempt to produce surfaces which might diminish biomaterial-mediated thrombosis and inflammation, surface derivatization with 2-acrylamido-2-methylpropanesulphonic acid (AMPS) was carried out. The derivatization procedure generates free radicals which initiate the copolymerization of AMPS monomers directly to a polyurethane surface. In an in vitro blood loop study using non-anticoagulated human blood, the resulting AMPS-derivatized material completely abrogates the generation of fibrinopeptide A, decreases the production of beta-thromboglobulin and C3a, and decreases the adherence of platelets. The derivatized material also attracts fewer adherent neutrophils when implanted in mice. However, AMPS derivatization unexpectedly increases the recruitment of macrophages to implanted material and promotes the formation of adherent sleeve thrombi on central venous catheters indwelling in non-anticoagulated canine femoral veins. Thus, AMPS derivatization has highly variable effects on inflammatory and thrombotic systems. Further investigation is clearly required to determine the mechanisms underlying both desired and adverse effects.

Sulfonate-containing polyurethanes were evaluated for in vivo biodegradation using subcutaneously implanted tensile bars. In addition, these anionically charged polyurethanes were evaluated for in vivo activation of human complement C3a and ex vivo platelet deposition in arteriovenously-shunted canines. The sulfonate derivatized polymers included laboratory synthesized polyurethane and Biomer. Other polymers used for references included Intramedic polyethylene, Silastic and a poly(ethylene oxide) based polyurethane. The biodegradation results indicated that Biomer and the laboratory sulfonated Biomer (both manufactured with stabilizers), remained mechanically stable, retaining both tensile strength and elasticity after 4 weeks of subcutaneous implantation. The unstabilized polyurethanes (with or without sulfonation), however, showed marked cracking and a loss of mechanical properties after the same period of subcutaneous implantation. Sulfonated polyurethanes depressed human complement C3a activation in plasma, as indicated by decreased levels of anaphylatoxin production. The results of canine ex vivo blood contacting experiments were conducted in both an acute and chronic model and demonstrated decreased platelet deposition and activation for the sulfonated polyurethanes.

The revision of the subcellular model of hormone action is described, with an incorporation of potential autocrine mechanisms. A general overview of available assay methodologies considers the major disadvantages of earlier methods and describes in detail the current methodologies (sucrose gradient analysis, dextran-coated charcoal assays, ER-EIA, ERICA). A major concern with clinical correlations of response to hormone receptor levels is the quality assurance of the multicentric programs. Results from national and international programs are considered. The clinical correlations are divided into four major categories: (1) the response to hormone deprivation (oophorectomy or adrenalectomy), (2) the development of specific agents which exploit receptor mechanisms (antiestrogens) or inhibit steroid biosynthesis (aminoglutehimide), (3) the rates of recurrence of tumors following mastectomy, and (4) the correlation of hormone receptors with current adjuvant therapies.

Human peripheral blood lymphocytes (HPBL) were examined for the presence of cryptic Thomsen-Friedenreich (TF) antigens as detected by PNA or an anti-TF mAb (49H8) after neuraminidase treatment of the cell surface. Neither PNA nor the mAb bound to the cells before treatment with neuraminidase. After removal of surface sialic acid, all lymphocytes were PNA-reactive, and 85% of HPBL reacted with the mAb 49H8. Seventy-seven percent of nylon wool (NW)-eluted T cells (96% Leu 1+), 80% of enriched helper T cells (83% Leu 3a+), and 78% of suppressor/cytotoxic T cells (63% Leu 2a+) carried the cryptic TF determinant recognized by the mAb 49H8. Ninety-one percent of NW-adherent cells (68% Leu 10+, 5% Leu 1+) were also TF positive. In contrast to NW-eluted T cells which showed low to moderate mAb 49H8 binding, 48% of NW-adherent cells revealed strong binding of anti-TF mAb. With progressive activation of T cells by PHA, binding of mAb to the cryptic TF antigen completely disappeared on blast cells. The presence of TF antigens on small cells in the culture was only poorly affected. The same was observed for activation of B cells with PWM. On the other hand, binding sites for PNA did not change during blastogenesis. The disappearance of the particular, mAb 49H8-reactive TF antigen on T blast cells is not due to the loss of antigen in a distinct T cell subset, but occurs to an equal extent in the helper and suppressor/cytotoxic T cell subpopulations. Thus, the majority of peripheral T and B lymphocytes carries cryptic TF antigens. Activated T or B cell blasts, on the other hand, are deficient for the particular TF antigen detected by the mAb 49H8. We interpret these data as a modulation of certain TF antigens on effector cells in the course of lymphocyte activation.

The Thomsen-Friedenreich antigen (T-antigen) is a cryptic disaccharide structure on human erythrocytes and is supposed to be expressed in an unhidden form on carcinoma cells. We tested the ability of four anti-T reagents (i.e., peanut agglutinin, human and rabbit anti-T antisera, and monoclonal anti-T antibodies) to agglutinate neuraminidase treated human erythrocytes and compared their capacity to bind to the surface of human carcinoma cell lines or neuraminidase treated lymphocytes. We found that all of the reagents strongly agglutinated neuraminidase treated erythrocytes. In contrast, only peanut agglutinin and the monoclonal antibody bound to the surface of carcinoma cell lines and to neuraminidase treated lymphocytes. Peanut agglutinin was inhibited by D-galactose and is known to be specific for the T-disaccharide. The determinants on erythrocytes, lymphocytes, and carcinoma cells, recognized by peanut agglutinin, are resistant to trypsin treatment. The monoclonal antibody was specifically inhibited by phenyl-beta-D-galactoside. The binding sites on erythrocytes and lymphocytes for the monoclonal antibody can be removed by treatment with trypsin or Pronase. On the other hand, the binding sites on carcinoma cells are resistant to trypsin but can be removed with Pronase. In contrast to the peanut agglutinin binding sites on carcinoma cells the structures recognized by the monoclonal antibody cannot be further increased by neuraminidase treatment. Human and rabbit anti-T antisera did not bind to tumor cell surface or to neuraminidase treated lymphocytes. Hemagglutination of human anti-T could be inhibited by asialofetuin; the specificity of rabbit anti-T could not be established in this study. Hemagglutination with both antisera is resistant to trypsin but partially sensitive to Pronase treatment. These results indicate that each of the reagents has a distinct specificity and recognizes different antigenic determinants on different molecules. Only peanut agglutinin and monoclonal anti-T antibodies are able to detect common structures on the surface of neuraminidase treated erythrocytes and carcinoma cell lines.

Cryptic Thomsen-Friedenreich (TF) antigens were detected by the lectin peanut agglutinin (PNA) on the surface of murine lymphocytes after treatment of cells with neuraminidase. Thereby, a particular TF antigen could be distinguished using a monoclonal anti-TF antibody 49H8. In contrast to the known general galactoside specificity of PNA, the mAb was restricted to Gal beta(1-3)GalNAc/GlcNAc. Preincubation of cells with PNA abolished mAb 49H8 binding completely. However, only the intensity of staining with PNA was reduced by prior incubation of cells with the mAb. Cryptic TF antigens detected by the mAb were expressed on 39% of murine bone marrow cells, 88% of thymocytes, 62% of lymph node cells, and 65% of spleen cells. On the other hand, over 80% of the lymphatic cells carried cryptic PNA binding sites independent of the lymphoid organ they derived. In the thymus, a subpopulation of cells (76%) could be detected by PNA without neuraminidase treatment. Twenty-eight percent of thymocytes carried exposed mAb binding sites, too. All of them were shown to express further binding sites for PNA constantly. Therefore, a subpopulation of PNA-reactive, immature thymocytes can be distinguished by the mAb 49H8. During activation of splenic lymphocytes with PHA, the lymphoblasts completely lost their cryptic mAb binding sites while PNA reactivity was not affected. We conclude that the anti-TF mAb recognizes a particular TF antigen exposed on thymocytes and present in a cryptic form on other lymphocytes. The number of cells carrying mAb 49H8 binding sites varied, dependent on the organ from which the lymphocytes derived. PNA-reactive lymphocytes are distributed homogeneously in the lymphoid organs.

The molecules involved in homotypic aggregation of the human Burkitt-lymphoma cell line Raji were investigated by inhibition of reaggregation with carbohydrates and glycoconjugates, by inhibition of glycosylation, and enzyme treatment of the cell surface. Complete inhibition of reaggregation was achieved with bovine submaxillary mucin. Asialomucin, on the other hand, was not effective in this assay. Another potent inhibitor of reaggregation was the ganglioside GMI. The common carbohydrate structure of these molecules is NeuNAc-(gal)-galNAc. Lactosamine, fucosyllactosamine, sialyllactosamine, complex mannose type, or Thomsen-Friedenreich antigen sequences are not involved in aggregation. Neuraminidase and chloroquine also abolished agglutination of cells. The finding that mucin, but not asialomucin, inhibits the reaction, demonstrates the importance of sialic acid in this process. Homotypic aggregation was shown to be resistant to trypsin. Using the glycosylation inhibitor tunicamycin we show that N-glycosidically linked carbohydrate chains are involved in aggregation. Swainsonine or castanospermine, which inhibit processing of terminal sialyllactosamines to the mannose core, did not interfere with the reaction supporting the results of the inhibition assay. The data presented suggest the involvement of 2 molecules in homotypic aggregation of human Burkitt-lymphoma cells. One component is a lectin-like molecule containing N-linked carbohydrate chains. The other component carries the neuraminidase-sensitive and trypsin-resistant determinant NeuNAc-(gal)-galNAc and, therefore, appears to be a glycolipid. This proposed lectin-carbohydrate interaction in homotypic aggregation is further supported by the frequently observed dependence of lectins on divalent cations as indicated by inhibition of aggregation with EDTA and EGTA.

Thomsen-Friedenreich (TF) antibodies were prepared from human serum by different enrichment procedures. This resulted in three antibody preparations all of which agglutinated neuraminidase-treated erythrocytes. On the other hand, each of the three antibody populations showed a distinct specificity pattern. Anti-TF1 antibodies could be inhibited in the hemagglutination inhibition assay by asialofetuin, asialotransferrin, asialoglycophorin and asialomucin. The sialylated form of these glycoproteins showed no inhibition. No significant inhibition could be achieved with several mono- or disaccharides. This suggests that anti-TF1 recognizes common structures on glycoproteins normally hidden by sialic acid. Anti-TF2 antibodies showed specificity for asialofetuin, bovine submaxillary mucin, asialomucin, asialoglycophorin, the disaccharide gal-beta (1-3)N-acetyl-galactosamine (galNAc) and nitrophenyl-beta-galactoside. Because asialotransferrin or unbound lactosamine were not inhibitory, we suppose that the residual common structure of the inhibitors is (gal)-galNAc-O-Ser/Thr, which is present in high amounts in submaxillary mucin. Anti-TF3 antibodies were inhibited by asialoglycophorin but not by asialomucin or asialofetuin. Strong saccharide inhibitors were gal-beta (1-3)galNAc, nitrophenyl-beta-galactoside, as well as galactose. Therefore, both of the antibody preparations, anti-TF2 and anti-TF3, could be inhibited by gal-beta-(1-3)galNAc, but showed preference to one or the other sugar component of the disaccharide resulting in a differential recognition of glycoconjugate inhibitors. Anti-TF2 and anti-TF3 seem to recognize the carbohydrates in the context of a protein backbone, because gal-beta-(1-3)galNAc in connection with a ceramide backbone (GM1) was not inhibitory. When tested on three human breast cancer cell lines, only anti-TF2 recognized epitopes exposed on the cell surface. We, therefore, conclude that human serum contains at least three subpopulations of TF antibodies with distinct specificities. Only anti-TF2 can detect cryptic erythrocyte epitopes which are also exposed on human breast cancer cell lines.

Paraffin-embedded tissue sections of primary tumors and lymph node metastases of 80 breast cancer patients were tested for the expression of Thomsen-Friedenreich (TF) antigens with the aid of a monoclonal IgM antibody (49H8) highly specific for phenyl-beta-galactoside. TF antigens were not expressed in 16 different normal tissues with the exception of some structures in the kidney. In tumor cells, two types of antigen expression were found; namely, cryptic and exposed. From stage T1/No to stages T2-4/N1,2 the number of cases expressing high amounts of TF antigens increased from 9% (2/22) to 22% (4/18) while the percentage of patients with low intensity of antibody binding was reduced from 59% (13/22) to 39% (7/18). The total amount of TF-positive primary tumors at stages T2-4/No increased from 42% (8/19) to 69% (18/26) when lymph nodes were infiltrated (T2-4/N1,2). At this stage 80% (21/26) of the patients with lymph node infiltration carried TF antigens in the nodes. The distribution of antigens was heterogeneous among the tumor cells and was expressed mainly in an apical or luminal position. The increased expression of antigens was attributed to exposed TF antigens, while cryptic antigens remained constant. When primary tumors expressed exposed TF antigens, the corresponding lymph nodes also contained exposed antigen. The same was true for the cryptic antigen. The data demonstrate an increase in the intensity of TF antigen expression during tumor progression and a spread of TF-positive tumor cells into the axillary lymph nodes with an increasing number of breast cancer patients being TF-positive at this stage.

The rat uterus responds to estradiol (E2) and E2 benzoate stimulation with an increase in progesterone receptor production and with growth. These responses were also elicited to varying degrees by a series of estrogenic (ICI 77,949 and ICI 47,699) and antiestrogenic triphenylethylene derivatives [tamoxifen (TAM), 4-hydroxy-TAM (4-OH-TAM), and 4-CH3-TAM]. These compounds have a range of affinities for the estrogen receptor (ER) and are able to compete with [3H]E2 binding in the uterus in vivo. Within 1-2 h of a sc injection of high affinity ligands (E2, E2B, and 4-OH-TAM), there was decrease in cytosol ER. This decrease was also observed with TAM, which is metabolized to 4-OH-TAM in vivo. In contrast, there was no decrease in cytosolic ER in animals treated with low affinity compounds (ICI 77,949, ICI 47,699, and 4-CH3-TAM) at any time before the onset of an estrogenic response. Furthermore, the nuclear ER increased after administration of a high affinity ligand (E2), as measured by exchange assay, but no increase in nuclear ER was observed after administration of low affinity ligands (ICI 77,949 and 4-CH3-TAM), although estrogenic responses were produced. From these data we have suggested a functional model to explain ER-mediated events in the rat uterus that supports the recent proposal that unoccupied ER is located in the nuclear compartment. In this model, the majority of unoccupied ER may reside in the nucleus in vivo; however, when the cells are disrupted in vitro, the unoccupied receptor or dissociation of low affinity ligand-ER complex causes unoccupied receptor to fall out of the nucleus and be incorporated into the cytosolic fraction. The high affinity ligand-ER complexes are retained in the nucleus. This would suggest that the apparent translocation of the ER from the cytoplasm to the nucleus may be an artifact. The data may reflect differential extraction of unoccupied receptors from the nucleus rather than transfer of receptor complexes to the nucleus.

It has recently been reported that phenol red, a pH indicator present in most tissue culture media, is a weak estrogen that can stimulate some estrogen-sensitive cells. However, the relative impact of phenol red on various cell lines is controversial. We examined the effect of phenol red on several estrogen-responsive cell systems that we use to study estrogen action. These included estrogenic stimulation of progesterone receptor and growth in human breast cancer-derived MCF-7 cells, stimulation of growth in human breast cancer-derived T47D cells, stimulation of prolactin synthesis in primary cultures of immature rat pituitary cells, and stimulation of progesterone receptor in primary cultures of immature rat uterine cells. Estrogenic responses in MCF-7 cells were the most sensitive to the presence of phenol red, while the other three cell cultures showed lesser effects of the indicator. In addition to intrinsic differences in cell responses, there were several other factors involved. These included differences in the estrogenic activity of phenol red-containing media and phenol red itself from different commercial suppliers, and differences in the concentration of free phenol red in final media due to binding of the indicator by serum. Higher concentrations of serum reduced the impact of phenol red on estrogenic responses in primary pituitary cells. Phenol red added to rat uterine cytosol competed with estradiol for binding to the estrogen receptor (relative binding affinity (RBA) approx. 0.001), and the acidic and basic forms of the indicator showed similar activity. Some commercial phenol red samples inhibited cell growth at levels of 100 mg/l; these effects were toxic rather than antiestrogenic, because growth inhibition could not be competitively reversed by an excess of estradiol. The amount of the indicator bound to serum in the final media, the source of the phenol red and the sensitivity of different cell types to the indicator ultimately determine its influence to the response of cells in tissue culture.