Maternal vitamin D, DNA methylation at imprint regulatory regions and offspring weight at birth, 1 year and 3 years.

BACKGROUND/OBJECTIVE: Vitamin D deficiency during pregnancy is associated with poor birth outcomes in some studies, but few have examined weight beyond birth. In addition, little is known about how vitamin D influences DNA methylation of regulatory regions known to be involved in growth, as possible mediators to weight status in offspring. SUBJECTS/METHODS: We conducted linear regressions to assess maternal plasma 25-hydroxyvitamin D (25(OH)D) by quartile and birth weight for gestational age z-score, 1-year weight-for-length z-score and 3-year body mass index (BMI) z-score among 476 mother/infant dyads from a prospective cohort. We assessed maternal 25(OH)D and infant DNA methylation at nine differentially methylated regions (DMRs) of genomically imprinted genes with known functions in fetal growth, including H19, IGF2, MEG3, MEG3-IG, MEST, NNAT, PEG3, PLAGL1 and SGCE/PEG10. RESULTS: Mean (standard deviation, s.d.) maternal 25(OH)D was 41.1 (14.2) nmol l-m at a mean (s.d.) of 13.2 (5.5) weeks gestation. After adjustment for potential confounders, the first (Q1) and second (Q2) quartiles of 25(OH)D, compared to the fourth (Q4), were associated with lower birth weight for gestational age z-scores (-0.43 units; CI: -0.79, -0.07; P=0.02 for Q1 and -0.56 units; CI: -0.89, -0.23; P=0.001 for Q2). Q1 compared to Q4 was associated with higher 1-year weight-for-length z-scores (0.78 units; 0.08, 1.54; P=0.04) and higher 3-year BMI z-scores (0.83 units; 0.11, 0.93; P=0.02). We did not observe associations between maternal 25(OH)D and methylation for any of the nine DMRs after correcting for multiple testing. CONCLUSIONS: Reduced maternal 25(OH)D was associated with lower birth weight for gestational age z-scores but higher 1-year weight-for-length and 3-year BMI z-scores in offspring. However, 25(OH)D does not appear to be operating through the regulatory sequences of the genomically imprinted genes we examined.

Newborns of obese parents have altered DNA methylation patterns at imprinted genes.

BACKGROUND: Several epidemiologic studies have demonstrated associations between periconceptional environmental exposures and health status of the offspring in later life. Although these environmentally related effects have been attributed to epigenetic changes, such as DNA methylation shifts at imprinted genes, little is known about the potential effects of maternal and paternal preconceptional overnutrition or obesity. OBJECTIVE: We examined parental preconceptional obesity in relation to DNA methylation profiles at multiple human imprinted genes important in normal growth and development, such as: maternally expressed gene 3 (MEG3), mesoderm-specific transcript (MEST), paternally expressed gene 3 (PEG3), pleiomorphic adenoma gene-like 1 (PLAGL1), epsilon sarcoglycan and paternally expressed gene 10 (SGCE/PEG10) and neuronatin (NNAT). METHODS: We measured methylation percentages at the differentially methylated regions (DMRs) by bisulfite pyrosequencing in DNA extracted from umbilical cord blood leukocytes of 92 newborns. Preconceptional obesity, defined as BMI ⩾30 kg m(-2), was ascertained through standardized questionnaires. RESULTS: After adjusting for potential confounders and cluster effects, paternal obesity was significantly associated with lower methylation levels at the MEST (ß=-2.57; s.e.=0.95; P=0.008), PEG3 (ß=-1.71; s.e.=0.61; P=0.005) and NNAT (ß=-3.59; s.e.=1.76; P=0.04) DMRs. Changes related to maternal obesity detected at other loci were as follows: ß-coefficient was +2.58 (s.e.=1.00; P=0.01) at the PLAGL1 DMR and -3.42 (s.e.=1.69; P=0.04) at the MEG3 DMR. CONCLUSION: We found altered methylation outcomes at multiple imprint regulatory regions in children born to obese parents, compared with children born to non-obese parents. In spite of the small sample size, our data suggest a preconceptional influence of parental life-style or overnutrition on the (re)programming of imprint marks during gametogenesis and early development. More specifically, the significant and independent association between paternal obesity and the offspring's methylation status suggests the susceptibility of the developing sperm for environmental insults. The acquired imprint instability may be carried onto the next generation and increase the risk for chronic diseases in adulthood.

Acute toxicity of hypofractionated intensity-modulated radiotherapy for prostate cancer.

BACKGROUND: Dose-escalated hypofractionated radiotherapy (hfrt) using intensity-modulated radiotherapy (imrt), with inclusion of the pelvic lymph nodes (plns), plus androgen suppression therapy (ast) in high-risk prostate cancer patients should improve patient outcomes, but acute toxicity could limit its feasibility. METHODS: Our single-centre phase ii prospective study enrolled 40 high-risk prostate cancer patients. All patients received hfrt using imrt with daily mega-voltage computed tomography imaging guidance, with 95% of planning target volumes (ptv68 and ptv50) receiving 68 Gy and 50 Gy (respectively) in 25 daily fractions. The boost volume was targeted to the involved plns and the prostate (minus the urethra plus 3 mm and minus 3 mm from adjacent rectal wall) and totalled up to 75 Gy in 25 fractions. Acute toxicity scores were recorded weekly during and 3 months after radiotherapy (rt) administration. RESULTS: For the 37 patients who completed rt and the 3-month follow-up, median age was 65.5 years (range: 50-76 years). Disease was organ-confined (T1c-T2c) in 23 patients (62.1%), and node-positive in 5 patients (13.5%). All patients received long-term ast. Maximum acute genitourinary (gu) and gastrointestinal (gi) toxicity peaked at grade 2 in 6 of 36 evaluated patients (16.6%) and in 4 of 31 evaluated patients (12.9%) respectively. Diarrhea and urinary frequency were the chief complaints. Dose-volume parameters demonstrated no correlation with toxicity. The ptv treatment objectives were met in 36 of the 37 patients. CONCLUSIONS: This hfrt dose-escalation trial in high-risk prostate cancer has demonstrated the feasibility of administering 75 Gy in 25 fractions with minimal acute gi and gu toxicities. Further follow-up will report late toxicities and outcomes.

Associations between antibiotic exposure during pregnancy, birth weight and aberrant methylation at imprinted genes among offspring.

OBJECTIVES: Low birth weight (LBW) has been associated with common adult-onset chronic diseases, including obesity, cardiovascular disease, type II diabetes and some cancers. The etiology of LBW is multi-factorial. However, recent evidence suggests exposure to antibiotics may also increase the risk of LBW. The mechanisms underlying this association are unknown, although epigenetic mechanisms are hypothesized. In this study, we evaluated the association between maternal antibiotic use and LBW and examined the potential role of altered DNA methylation that controls growth regulatory imprinted genes in these associations. METHODS: Between 2009-2011, 397 pregnant women were enrolled and followed until delivery. Prenatal antibiotic use was ascertained through maternal self-report. Imprinted genes methylation levels were measured at differentially methylated regions (DMRs) using bisulfite pyrosequencing. Generalized linear models were used to examine associations among antibiotic use, birth weight and DMR methylation fractions. RESULTS: After adjusting for infant gender, race/ethnicity, maternal body mass index, delivery route, gestational weight gain, gestational age at delivery, folic acid intake, physical activity, maternal smoking and parity, antibiotic use during pregnancy was associated with 138 g lower birth weight compared with non-antibiotic use (ß-coefficient=-132.99, s.e.=50.70, P=0.008). These associations were strongest in newborns of women who reported antibiotic use other than penicillins (ß-coefficient=-135.57, s.e.=57.38, P=0.02). Methylation at five DMRs, IGF2 (P=0.05), H19 (P=0.15), PLAGL1 (P=0.01), MEG3 (P=0.006) and PEG3 (P=0.08), was associated with maternal antibiotic use; among these, only methylation at the PLAGL1 DMR was also associated with birth weight. CONCLUSION: We report an inverse association between in utero exposure to antibiotics and lower infant birth weight and provide the first empirical evidence supporting imprinted gene plasticity in these associations.

Analysis of intraprostatic therapeutic effects in prostate cancer patients using [(11)C]-choline pet/ct after external-beam radiation therapy.

PURPOSE: The objective of the present study was to analyze, with relatively high sensitivity and specificity, uptake properties of [(11)C]-choline in prostate cancer patients by means of positron-emission tomography (pet)/computed tomography (ct) imaging using objectively defined pet parameters to test for statistically significant changes before, during, and after external-beam radiation therapy (ebrt) and to identify the time points at which the changes occur. METHODS: The study enrolled 11 patients with intermediate-risk prostate cancer treated with ebrt, who were followed for up to 12 months after ebrt. The [(11)C]-choline pet scans were performed before treatment (baseline); at weeks 4 and 8 of ebrt; and at 1, 2, 3, 6, and 12 months after ebrt. RESULTS: Analysis of [(11)C]-choline uptake in prostate tissue before treatment resulted in a maximum standardized uptake value (suvmax) of 4.0 ± 0.4 (n = 11) at 40 minutes after injection. During week 8 of ebrt, the suvmax declined to 2.9 ± 0.1 (n = 10, p < 0.05). At 2 and 12 months after ebrt, suvmax values were 2.3 ± 0.3 (n = 10, p < 0.01) and 2.2 ± 0.2 (n = 11, p < 0.001) respectively, indicating that, after ebrt, maximum radiotracer uptake in the prostate was significantly reduced. Similar effects were observed when analyzing the tumour:muscle ratio (tmr). The tmr declined from 7.4 ± 0.6 (n = 11) before ebrt to 6.1 ± 0.4 (n = 11, nonsignificant) during week 8 of ebrt, to 5.6 ± 0.03 (n = 11, p < 0.05) at 2 months after ebrt, and to 4.4 ± 0.4 (n = 11, p < 0.001) at 12 months after ebrt. CONCLUSIONS: Our study demonstrated that intraprostatic [(11)C]-choline uptake in the 11 analyzed prostate cancer patients significantly declined during and after ebrt. The pet parameters SUVmax and tmr also declined significantly. These effects can be detected during radiation therapy and up to 1 year after therapy. The prognostic value of these early and statistically significant changes in intraprostatic [(11)C]-choline pet avidity during and after ebrt are not yet established. Future studies are indicated to correlate changes in [(11)C]-choline uptake parameters with long-term biochemical recurrence to further evaluate [(11)C]-choline pet changes as a possible, but currently unproven, biomarker of response.

Bleeding per vaginam is associated with funisitis in women with preterm prelabour rupture of the fetal membranes.

OBJECTIVE: To evaluate the risk of funisitis among women with preterm prelabour rupture of the membranes (PPROM) and subsequent bleeding per vaginam. DESIGN: Prospective cohort study. SETTING: A University Hospital in the USA. POPULATION: A total of 157 women with PPROM, divided into those with bleeding per vaginam during the hospital admission (n = 46) and those without bleeding per vaginam (n = 111). METHODS: Pathologist blinded to bleeding status assessed placental pathology for funisitis. MAIN OUTCOME MEASURES: Funisitis. RESULTS: Women with bleeding per vaginam were more likely to have funisitis (67.4% versus 36%, P < 0.001) compared with those without bleeding. Logistic regression demonstrated that bleeding per vaginam predicted funisitis after controlling for gestational age at admission, latency period and gestational age at delivery. CONCLUSIONS: Among women with PPROM, those with bleeding per vaginam are more likely to have funisitis than those without bleeding per vaginam.

Intraoperative factors associated with stranded source placement accuracy in low-dose-rate prostate brachytherapy.

PURPOSE: The quality of a low-dose rate prostate brachytherapy implant depends on the accurate placement of sources in their planned locations. This study investigates intraoperative factors that potentially contribute to stranded source placement inaccuracy in prostate brachytherapy. METHODS AND MATERIALS: Intraoperative video images of the brachytherapist's hand motions and needle insertions during the implant procedure were acquired for analysis. Using video analysis software, maximum and average needle insertion velocities were determined. The number of needle insertion attempts and the use of the brachytherapist's other hand to manipulate the needle direction were also recorded. Sources misplacements were analyzed using an ultrasound-based method described elsewhere. RESULTS: Fifteen patients agreed to undergo this study; 1619 125I seeds were inserted using 357 needles; 1197 seeds were confidently identified using ultrasound images and included in the analysis. The mean overall misplacement was 0.49 cm (0-2 cm, 95% CI = 0.47-0.51); 614 seeds were delivered with a single pass and 583 seeds with >1 passes (range 2-6). The mean maximum needle velocity was 12.34 cm s-1 (range 4-28 cm s-1) and mean average velocity was 4.76 cm s-1 (range 0.4-17.4 cm s-1); 747 seeds were delivered with manipulation of the needle. The generalized linear model test was used to analyze factors contributing to seed misplacement, and it was found that a maximum speed <12 cm s-1 was associated with a decrease in seed misplacement by 0.049 cm vs. a maximum speed >12 cm s-1, p = 0.0121). Other evaluated factors were found to have no statistically significant correlation with seed misplacement: average speed (p = 0.4947), manual manipulation of needle (p = 0.9264), and number of needle passes (p = 0.8907). CONCLUSIONS: This study identified that needles inserted with lower maximum velocity were associated with less seed misplacement. Manual manipulation of the needle, number of passes, and average speed did not show statistically significant correlation with seed misplacement.

Using antifibrinolytics in the peripartum period - concern for a hypercoagulable effect?

INTRODUCTION: Although antifibrinolytic agents are used to prevent and treat hemorrhage, there are concerns about a potential increased risk for peripartum venous thromboembolism. We sought to determine the impact of tranexamic acid and ɛ-aminocaproic acid on in vitro clotting properties in pregnancy. METHODS: Blood samples were obtained from healthy pregnant, obese, and preeclamptic pregnant women (n = 10 in each group) prior to delivery as well as from healthy non-pregnant controls (n = 10). Maximum clot firmness (MCF) and clotting time (CT) were measured using rotation thromboelastometry in the presence of tranexamic acid (3, 30, or 300 µg/mL) or ɛ-aminocaproic acid (30, 300, or 3000 µg/mL). ANOVA and regression analyses were performed. RESULTS: Mean whole blood MCF was significantly higher in healthy pregnant vs. non-pregnant women (66.5 vs. 57.5 mm, p < 0.001). Among healthy pregnant women, there was no significant difference between mean MCF (whole blood alone, and with increasing tranexamic acid doses = 66.5, 66.1, 66.4, 66.3 mm, respectively; p = 0.25) or mean CT (409, 412, 420, 424 sec; p = 0.30) after addition of tranexamic acid. Similar results were found using ɛ-aminocaproic acid. Preeclamptic women had a higher mean MCF after the addition of ɛ-aminocaproic acid and tranexamic acid (p = 0.05 and p = 0.04, respectively) compared to whole blood alone. CONCLUSIONS: Pregnancy is a hypercoagulable state, as reflected by an increased MCF compared to non-pregnant women. Addition of antifibrinolytic therapy in vitro does not appear to increase MCF or CT for non-pregnant, pregnant, and obese women. Whether antifibrinolytics are safe in preeclampsia may require further study.

Direct evidence that apoptosis enhances tumor responses to fractionated radiotherapy.

Currently, the contribution of cellular apoptotic sensitivity to tumor response after radiation therapy remains controversial. To address this issue, the survival of Rat-1 fibroblasts containing a 4-hydroxytamoxifen-regulated c-Myc allele, c-MycER (T. D. Littlewood et al., Nucleic Acids Res., 23: 1686-1690, 1995), after single and fractionated doses of radiation was investigated. This model system allows pharmacological regulation of apoptosis sensitivity in the same cells in vitro and as xenograft tumors derived from these cells in vivo (G. I. Evan et al., Cell, 69: 119-128, 1992; R. M. Alarcon et al., Cancer Res., 56: 4315-4319, 1996). Activating c-MycER in vitro resulted in marked sensitization of Rat-1 fibroblasts to the effects of both single-dose and fractionated irradiation as measured by the induction of apoptosis and clonogenic survival. Overexpression of the antiapoptosis protein Bcl-2 suppressed the induction of apoptosis and increased clonogenic survival in cells with activated c-Myc after single-dose and fractionated radiation. Systemic time-release implant delivery of 4-hydroxytamoxifen to severe combined immunodeficient mice bearing Rat-1-MycER tumors over the course of either single-dose (10 Gy) or fractionated (five fractions of 2 Gy) radiotherapy resulted in prolonged tumor growth delay relative to identical tumors from mice that received placebo implants. Furthermore, tumors derived from Rat-1-MycER cells that overexpressed Bcl-2 exhibited shorter tumor growth delays relative to similarly treated Rat-1-MycER tumors. The length of tumor growth delay after single-dose or fractionated radiotherapy strongly correlated with the extent of radiation-induced apoptosis in the xenograft tumors as measured by terminal deoxynucleotidyl transferase-mediated nick end labeling. These in vivo results provide direct evidence that increasing the sensitivity of tumor cells to die by apoptosis increases the efficacy of fractionated radiotherapy by reducing tumor cell clonogenic survival.

Obstetric hemorrhage survey: Attitudes and practices of maternal-fetal medicine fellows.

OBJECTIVE: To evaluate experiences related to obstetric hemorrhage and suspected abnormal placentation among first year maternal-fetal medicine fellows. STUDY DESIGN: A cross-sectional anonymous survey was administered at the Society for Maternal-Fetal Medicine fellow retreat in March 2013. Fellows were asked about management strategies that reflected both their individual and institutional practices. RESULTS: There was a 56% response rate (55/98). In cases of postpartum hemorrhage due to uterine atony, there was variable use of the uterine tamponade device. The median incremental time for balloon deflation was every 5 hours (IQR = 2-12). Compared to the east coast, fellows from the west coast performed more hysterectomies (mean±SD; 2.9±2.4 vs. 1.2±1.2, p = 0.004). During a peripartum hysterectomy, 29% of fellows used a handheld cautery device such as Ligasure® or Gyrus®. Fifty-six percent responded that their institution never recommend planned delayed hysterectomies for abnormal placental implantation. CONCLUSION: There is wide variation in practice among first year maternal-fetal medicine fellows in management of peripartum hysterectomy and postpartum hemorrhage.

Abbreviated course of radiation therapy in older patients with glioblastoma multiforme: a prospective randomized clinical trial.

PURPOSE: To prospectively compare standard radiation therapy (RT) with an abbreviated course of RT in older patients with glioblastoma multiforme (GBM). PATIENTS AND METHODS: One hundred patients with GBM, age 60 years or older, were randomly assigned after surgery to receive either standard RT (60 Gy in 30 fractions over 6 weeks) or a shorter course of RT (40 Gy in 15 fractions over 3 weeks). The primary end point was overall survival. The secondary end points were proportionate survival at 6 months, health-related quality of life (HRQoL), and corticosteroid requirement. HRQoL was assessed using the Karnofsky performance status (KPS) and Functional Assessment of Cancer Therapy-Brain (FACT-Br). RESULTS: All patients had died at the time of analysis. Overall survival times measured from randomization were similar at 5.1 months for standard RT versus 5.6 months for the shorter course (log-rank test, P =.57). The survival probabilities at 6 months were also similar at 44.7% for standard RT versus 41.7% for the shorter course (lower-bound 95% CI, -13.7). KPS scores varied markedly but were not significantly different between the two groups (Wilcoxon test, P =.63). Low completion rates of the FACT-Br (45%) precluded meaningful comparisons between the two groups. Of patients completing RT as planned, 49% of patients (standard RT) versus 23% required an increase in posttreatment corticosteroid dosage (chi(2) test, P =.02). CONCLUSION: There is no difference in survival between patients receiving standard RT or short-course RT. In view of the similar KPS scores, decreased increment in corticosteroid requirement, and reduced treatment time, the abbreviated course of RT seems to be a reasonable treatment option for older patients with GBM.

Review of low-dose-rate radiobiology for clinicians.

The use of therapeutic modalities that employ low-dose-rate (LDR) radiation is becoming increasingly prevalent in the clinic (eg, systemic targeted radiation therapy and brachytherapy). A natural tendency for radiation oncologists as they become familiar with these new therapies is to make predictions regarding efficacy and toxicity based on extrapolations from high-dose-rate radiobiology. If unfounded, these extrapolations could be misleading. This article discusses general principles of LDR radiobiology applicable to radioimmunotherapy.

Long-term follow-up of patients with Stage III follicular lymphoma treated with primary radiotherapy at Stanford University.

PURPOSE: To report the long-term survival and late toxicity data of Stage III follicular lymphoma patients treated with primary radiotherapy. METHODS AND MATERIALS: Sixty-six patients with Stage III follicular small cleaved (FSC) or follicular mixed (FM) non-Hodgkin's lymphoma were treated with total lymphoid irradiation (61 patients) or whole body irradiation (5 patients) as their primary treatment modality from 1963 to 1982 at Stanford University. Adjuvant chemotherapy was given to 13 patients. RESULTS: Median follow-up was 9.5 years with a range of 0.5-24.3 years. Median overall survival, cause-specific survival, freedom from relapse, and event-free survival were 9.5, 18.9, 7.1, and 5.1 years, respectively. Few initial relapses or lymphoma-related deaths were seen beyond the first decade of follow-up. Patient age and number of disease sites were the two strongest predictors of overall survival. The cohort of patients with limited Stage III disease demonstrated an 88% freedom from relapse and a 100% cause-specific survival with up to 23.5 years follow-up. CONCLUSION: The long-term survival data for Stage III FSC or FM non-Hodgkin's lymphoma treated with primary radiotherapy are at least comparable and possibly better than results achieved with other therapeutic approaches. Patients with limited Stage III disease do particularly well. Whether these results are superior to an initial approach of deferred therapy until clinically indicated is currently unknown.

Muscle-invasive transitional cell carcinoma of the urinary bladder: a population-based study of patterns of care and prognostic factors.

PURPOSE: Population-based cancer registries can permit the study of the survivorship of all patients with a particular diagnosis regardless of patterns of referral and practice within a specific geographic distribution. The purpose of this study is to describe the patterns of care, outcome, and prognostic factors for bladder cancer in the northern region of the province of Alberta, Canada, between 1984 and 1993. METHODS AND MATERIALS: Between 1984 and 1993, 184 patients from northern Alberta were identified from the Alberta Cancer Registry as having undergone curative treatment for biopsy-proven muscle-invasive transitional cell carcinoma of the bladder. Data were obtained, by retrospective chart review, regarding the staging, pathology, treatment, and outcome of patients treated in the northern Alberta cities of Edmonton, Grande Prairie, and Red Deer, regardless of the responsible treating institution. The prognostic significance of patient-, tumor-, and treatment-related variables were tested using univariate and multivariate analysis using the Cox proportional-hazard model. RESULTS: As the primary treatment modality, 74 patients (40%) received radical radiotherapy (RT) without surgery; surgery was used alone in 81 patients (44%), and was combined with preoperative or postoperative radiotherapy in 29 patients (16%). Seventy-three (40%) patients also received concurrent, neoadjuvant, or adjuvant chemotherapy. The Kaplan-Meier estimate of median survival was 2.2 years, and the 5-year overall survival was 30%. Univariate analysis demonstrated the prognostic significance of T classification (p < 0.001), lymph node involvement (p < 0.001), complete response to RT (p = 0.001), hydronephrosis (p = 0.017), and vascular/lymphatic involvement (p = 0.035). Multivariate analysis revealed the following to have a significant association with survival: T classification (p = 0.001), lymph node involvement (p = 0.004), complete response to RT (p = 0.054), hydronephrosis (p = 0.019), and use of chemotherapy in the treatment regimen (p = 0.025). CONCLUSION: The strongest prognostic factors in this study were tumor related, and no significant differences in survival were detected between patients treated with primary surgery vs. organ-preservation approaches. A survival advantage associated with the incorporation of chemotherapy into the management schema was detected on multivariate, but not univariate, analysis. Stratification of patients based on tumor characteristics is imperative in clinical trials for invasive bladder cancer. Novel treatment approaches are required to improve survival further in patients with apparently localized disease.

Myc activation reduces fibroblast clonogenicity via an apoptotic mechanism that can be suppressed by a soluble paracrine factor.

The c-Myc transcription factor is involved in the regulation of cellular proliferation and differentiation and is one of the most frequently deregulated genes in human cancers. While c-Myc is known to enhance the proliferative potential of cells, its activation in immortalized fibroblasts has been found to result in apoptosis following gamma-irradiation or under adverse growth conditions, including serum deprivation and hypoxia. When plating Rat-1 fibroblasts at low cell densities (100 cells/100 mm plate), we observed a substantial reduction in the clonogenicity of cells with deregulated c-Myc activity compared to cells with normal c-Myc activity. This difference in clonogenicity was apparent despite the fact that cells were plated in media containing sufficient serum and oxygen concentrations known to suppress apoptosis of exponentially growing Rat-1 fibroblasts with activated c-Myc. Therefore, we hypothesized that the observed reduction in plating efficiency in cells with activated c-Myc occurred via an apoptotic mechanism and that a fibroblast-derived factor was required for suppression of apoptosis. Overexpression of the anti-apoptotic oncogene, Bcl-2, in cells with activated c-Myc restored the plating efficiency to normal levels in cells plated at low cell densities. This strongly suggested that the decreased clonogenicity of fibroblasts with altered c-Myc activity resulted from enhanced apoptosis of the cells under these conditions. Furthermore, plating cells on a feeder layer of lethally-irradiated fibroblasts or in Rat-1 conditioned media increased the plating efficiencies of sparsely plated cells in a dose-dependent fashion. These results suggest that in addition to previously reported requirements for serum-derived growth factors and normal oxygen conditions, a paracrine factor liberated by Rat-1 fibroblasts is required to suppress c-Myc-induced apoptosis in these cells.

Maternal serum granulocyte-colony stimulating factor in preterm birth with subclinical chorioamnionitis.

Preterm birth has been linked with intrauterine infection and inflammation. Serum and amniotic fluid markers of inflammation, such as interleukin-1 (IL-1), IL-6, and granulocyte-colony stimulating factor (G-CSF), have been associated with clinical chorioamnionitis and preterm delivery. As G-CSF regulates the production and maturation of neutrophils, we sought to determine if maternal serum G-CSF levels are elevated in patients with preterm birth with subclinical histologic chorioamnionitis. Maternal serum G-CSF levels were significantly different among five groups of women studied (P < .001, Kruskall-Wallis test), and were highest in subjects with preterm labor who delivered preterm (P < .05, Mann-Whitney U test). Among women with preterm labor who delivered preterm, maternal serum G-CSF levels were significantly higher if histologic chorioamnionitis was present than when histologic evidence of infection was not present (P = 0.04, Mann-Whitney U test). Intrauterine infection may cause a local inflammatory process and initiate preterm labor. This inflammatory response may include production of G-CSF, which would enter the circulation and stimulate the migration of neutrophils to the site of infection. Our data support this concept, as maternal serum G-CSF is elevated with subclinical infection in association with preterm birth.

Maternal serum interleukin-6 concentration as a marker for impending preterm delivery.

OBJECTIVE: To determine whether serum interleukin-6 concentrations predict impending preterm delivery. METHODS: Blood samples were collected from 130 gravidas at 22-34 weeks' gestation. The study group consisted of 89 women evaluated for preterm contractions or premature rupture of membranes, and these women were compared with 41 outpatient controls without evidence of labor or infection, chosen by clinicians at the time of routine prenatal visits. Serum interleukin-6 concentrations were measured using a specific enzyme-linked immunosorbent assay kit. Analyses were by the Mann-Whitney U and the Kruskal-Wallis tests. RESULTS: All 41 control subjects had serum interleukin-6 concentrations less than 8 pg/mL. Sixteen of the 89 study patients had serum interleukin-6 concentrations greater than or equal to 8 pg/mL and 73 had values less than 8 pg/mL. When the serum interleukin-6 concentration was at least 8 pg/mL, the median interval from collection to delivery was significantly shorter than that among study and control subjects with serum interleukin-6 less than 8 pg/mL (5.5 versus 240 and 1801 hours, respectively; P < .001). The median gestational age at delivery was significantly lower when the serum interleukin-6 concentration was at least 8 pg/mL, compared with study and control subjects with serum interleukin-6 concentrations less than 8 pg/mL (29.6 versus 33.4 and 39.0 weeks, respectively; P < .001). In patients with preterm contractions, the interval from collection to delivery was significantly shorter when the serum interleukin-6 concentration was at least 8 pg/mL than when it was less than 8 pg/mL (3 versus 600 hours, P < .001). Similarly, the median gestational age at delivery was significantly lower when serum interleukin-6 was at least 8 pg/mL (29.0 versus 36.1 weeks, P < .001). CONCLUSION: Maternal serum interleukin-6 concentrations appear to be elevated in women destined to deliver prematurely. Measurement of this cytokine may prove useful in treating patients at high risk for preterm delivery.

Umbilical venous D-dimer concentrations with and without labor.

OBJECTIVE: To determine if labor activates the fetal fibrinolytic system. METHODS: A total of 59 umbilical venous blood samples were collecting following vaginal delivery at term (n = 20), cesarean delivery following labor at term (n = 12), vaginal delivery before term (n = 18), and cesarean delivery without labor (n = 9). D-dimer concentrations, a sensitive marker of fibrinolysis, were measured by enzyme-linked immunosorbent assay, and compared between groups by Kruskel-Wallis and Mann Whitney U tests, with significance defined as P < .05. RESULTS: There were no significant differences in median D-dimer concentrations between newborns delivered vaginally or by cesarean after term labor or preterm labor. There were significant differences in median umbilical venous D-dimer concentrations in subjects delivered vaginally or by cesarean after term or preterm labor compared with term subjects without labor delivered by cesarean (427, 773, and 326 versus 87 ng/mL, P = .01). CONCLUSION: Elevation of umbilical plasma D-dimer concentrations in laboring patients suggests activation of fetal fibrinolysis before delivery.

Repeated fetal betamethasone treatment and birth weight and head circumference.

OBJECTIVE: To assess the effect of repeated courses of betamethasone on birth weight and head circumference. METHODS: We conducted a historical cohort study of inpatients receiving betamethasone therapy over 5 years. We compared birth weights and head circumferences of infants whose mothers received one course of betamethasone with those of infants whose mothers received multiple courses. Multiple regression analysis was used to adjust for potential confounding variables. Sufficient power (80%) existed to detect a 20% difference between the groups (alpha = 0.05). RESULTS: Mean birth weights (+/-SD) were 1717 +/- 707 g in the single-course group (n = 107) and 1783 +/- 647 g in the multiple-course group (n = 45) (P =.59, Student t-test). Mean head circumference was 28.2 +/- 3.6 cm in the single-course group and 29.2 +/- 2.9 cm in the multiple-course group (P =.15, Student t-test). In regression analysis, birth weights (1757 g and 1752 g) and head circumferences (28.5 cm and 29.0 cm) did not differ significantly different between the single-course and multiple-course groups. CONCLUSION: Multiple courses of betamethasone do not reduce birth weight or head circumference in neonates compared with single-course therapy.