The association between threatened preterm labour and perinatal outcomes at term: a population-based cohort study.

OBJECTIVE: To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term. DESIGN: A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term. SETTING: Nova Scotia, Canada. POPULATION: All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019. METHODS: Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not. MAIN OUTCOME MEASURES: Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity. RESULTS: Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54). CONCLUSIONS: Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.

Guideline No. 401: sonographic cervical length in Singleton Pregnancies: techniques and clinical applications

To assess the association between sonography-derived cervical length measurement and preterm birth. To describe the various techniques to measure cervical length using sonography. To review the natural history of the short cervix. To review the clinical uses, predictive ability, and utility of sonography-measured short cervix. Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions. Intended Users Clinicians involved in the obstetrical management or cervical imaging of patients at increased risk of a short cervix. Women at increased risk of a short cervix or at risk of preterm birth. Literature published up to June 2019 was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, cervical insufficiency, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The evidence and this guideline were reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made and graded according to the rankings of the Canadian Task Force on Preventive Health Care ( Online Appendix Table A1). Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the sonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth.

Nutrient-induced spore germination of a Bacillus amyloliquefaciens biocontrol agent on wheat spikes.

AIMS: In this study, we investigated the feasibility of applying nutrient germinants to plant surfaces to stimulate the spore germination of the plant disease biocontrol agent Bacillus amyloliquefaciens strain TrigoCor. METHODS AND RESULTS: Using the terbium chloride assay and phase-contrast microscopy, we screened potential germinants of TrigoCor spores and found that a combination of d-glucose, d-fructose and potassium chloride (GFK), in addition to either l-asparagine (Asn-GFK) or l-alanine (Ala-GFK), induced maximal levels of TrigoCor spore germination in vitro. The germinant mixture Asn-GFK was also able to significantly stimulate Bacillus spore germination on wheat surfaces. CONCLUSIONS: The successful in vivo stimulation of Bacillus spore germination suggests that nutrient-induced spore germination on plant surfaces is a feasible strategy for improving Bacillus biocontrol. SIGNIFICANCE AND IMPACT OF THE STUDY: One of the challenges of applying Bacillus biological control agents to aboveground plant parts is that Bacillus cells transition to a metabolically dormant spore state on plant surfaces, making them unable to prevent subsequent pathogen attacks. This study demonstrates that using nutrients to stimulate Bacillus spore germination in vivo is a promising option for improving disease control and should be pursued further.

Iturin levels on wheat spikes linked to biological control of Fusarium head blight by Bacillus amyloliquefaciens.

The TrigoCor strain of Bacillus amyloliquefaciens provides consistent control against Fusarium head blight of wheat in controlled settings but there is a lack of disease and deoxynivalenol suppression in field settings. Since production of antifungal compounds is thought to be the main mode of action of TrigoCor control, we quantified levels of a key family of antifungal metabolites, iturins, as well as monitored Bacillus populations on wheat spikes over 14 days post-application in both the greenhouse and the field. We found that initial iturin levels on spikes in the greenhouse were three times greater than on spikes in the field, but that by 3 days post-application, iturin levels were equivalent and very low in both settings. We also determined that iturins declined rapidly over a 3-day post-application period on wheat spikes in both environments, despite the presence of significant Bacillus populations. Greenhouse trials and antibiosis tests indicated that the lower iturin levels on wheat spikes in the field could be a major factor limiting disease control in field settings. Future efforts to improve Bacillus disease control on wheat spikes and in the phyllosphere of various plants should focus on maintaining higher levels of iturins over critical infection periods.

Transvaginal ultrasonographic measurement of cervical length in asymptomatic high-risk women with a short cervical length in the previous pregnancy.

OBJECTIVE: To determine if asymptomatic women at high risk of preterm delivery who had a short cervical length in their previous pregnancy and delivered at term are at increased risk of having a short cervical length in their next pregnancy, and whether they are at increased risk of preterm birth. METHODS: This retrospective cohort study included high-risk (those with a history of spontaneous preterm birth, uterine anomaly or excisional treatment for cervical dysplasia) asymptomatic women who were pregnant with a singleton gestation delivering between April 2003 and March 2010, who had had a previous pregnancy and who had transvaginal ultrasonographic cervical length measurement performed at 16-30 weeks' gestation in both pregnancies. Comparison was among women who had a short cervical length (< 3.0 cm) in their previous pregnancy but delivered at term in that pregnancy (Short Term Group), women with a history of a normal cervical length (≥ 3.0 cm) in their previous pregnancy delivering at term (Long Term Group), and women who had a short cervical length (< 3.0 cm) in their previous pregnancy delivering preterm (Short Preterm Group). Primary outcomes were spontaneous preterm birth at < 37 weeks' gestation and cervical length. Secondary outcomes were spontaneous preterm birth at < 35 weeks and < 32 weeks, low birth weight, maternal outcomes and neonatal morbidity. RESULTS: A total of 62 women were included. Women in the Short Term Group were more likely to have a short cervical length in their next pregnancy compared with those in the Long Term Group (10/23 (43.5%) vs. 4/26 (15.4%), respectively) but not as likely as women in the Short Preterm Group (9/13 (69.2%); P=0.003). Women in the Short Term Group were not at an increased risk of spontaneous preterm birth at < 37 weeks in the next pregnancy compared with women in the Long Term Group (2/23 (8.7%) vs. 2/26 (7.7%), respectively), but women in the Short Preterm Group were at an increased risk (6/13 (46.2%); P<0.0001). Compared with women in the Short Term and Long Term groups, women in the Short Preterm Group were also at an increased risk of threatened preterm labor (6/23 (26.1%) and 4/26 (15.4%) vs. 9/13 (69.2%), respectively; P=0.002) and of receiving corticosteroids for fetal lung maturation (6/23 (26.1%) and 4/26 (15.4%) vs. 11/13 (84.6%), respectively; P<0.0001). CONCLUSION: Although high-risk asymptomatic women with a short cervical length in their previous pregnancy who delivered at term are at increased risk of having a short cervix in their next pregnancy, they are not at increased risk of preterm birth.

Effects of environmental tobacco smoke on perinatal outcomes: a retrospective cohort study.

OBJECTIVE: To evaluate the effects of environmental tobacco smoke (ETS) on perinatal outcomes. DESIGN: Retrospective cohort study. SETTING: Newfoundland and Labrador, Canada. POPULATION: Nonsmoking women with singleton gestations who delivered 1 April 2001-31 March 2009, identified through the Newfoundland and Labrador Provincial Perinatal Database. METHODS: Women who self-reported exposure to ETS were compared with those who reported no exposure. Univariate analyses and multivariate linear and logistic regression analyses (adjusting for maternal age, parity, partnered status, work status, level of education, body mass index, alcohol use, illicit drug use and gestational age) were performed and odds ratios(OR; or adjusted differences) with 95% confidence intervals were calculated. MAIN OUTCOME MEASURES: Birthweight, birth length, head circumference and stillbirth. Secondary outcomes included gestational age at delivery, preterm birth <37 and <34 weeks of gestation, prelabour rupture of membranes, Apgar score, endotracheal intubation for resuscitation, neonatal intensive care unit admission, congenital anomalies, respiratory distress syndrome, intraventricular haemorrhage, neonatal bacterial sepsis, jaundice and neonatal metabolic abnormalities. RESULTS: A total of 11,852 women were included: 1202(11.1%) exposed to ETS and 10,650 (89.9%) not exposed. Exposure to ETS was an independent risk factor for lower mean birthweight (-53.7 g, 95% CI -98.4 to -8.9 g), smaller head circumference (-0.24 cm, 95% CI -0.39 to -0.08 cm), shorter birth length (-0.29 cm, 95% CI -0.51 to -0.07 cm), stillbirth (OR 3.35, 95% CI 1.16-9.72, P = 0.026), and trends towards preterm birth <34 weeks (OR 1.87, 95% CI 1.00-3.53, P = 0.05) and neonatal sepsis (OR 2.96, 95% CI 0.99-8.86). CONCLUSIONS: Exposure of nonsmoking pregnant women to ETS is associated with a number of adverse perinatal outcomes including lower birthweight, smaller head circumference and stillbirth, as well as shorter birth length. This information is important for women, their families and healthcare providers, and reinforces the continued need for increased public policy and education on prevention of exposure to ETS.

Follow-up cervical length in asymptomatic high-risk women and the risk of spontaneous preterm birth.

OBJECTIVE: To determine whether further cervical length shortening by transvaginal ultrasonography in asymptomatic high-risk women with a short cervical length adds additional predictive value for spontaneous preterm birth and perinatal morbidity. STUDY DESIGN: Women with a history of spontaneous preterm birth, loop electrosurgical excision procedure, cone biopsy or uterine anomaly, who were pregnant with singleton gestations and were found by transvaginal ultrasonography to have a cervical length <3.0 cm at 20 to 28 weeks' gestation, and who underwent a follow-up cervical length within 3 weeks were evaluated, comparing those with further cervical length shortening (>10%) to those without further shortening. Primary outcomes were spontaneous preterm birth <35 weeks' gestation and perinatal morbidity. Secondary outcomes included spontaneous preterm birth <37 weeks, <34 weeks, <32 weeks, birth weight <2500 g, maternal and other neonatal outcomes. RESULT: Compared with women without further cervical shortening, those with further shortening were found by univariate analyses to have higher rates of spontaneous preterm birth <35 weeks (34.8 versus 8.5%, P = 0.014), <37 weeks (56.5 versus 21.3%, P = 0.003), <34 weeks (30.4 versus 2.1%, P = 0.001), <32 weeks (21.7 versus 0%, P = 0.003), birth weight <2500 g (60.9 versus 17.0%, P<0.0001), neonatal intensive care unit admission (47.8 versus 17.0%, P = 0.006) and composite perinatal morbidity (43.5 versus 14.9%, P = 0.009). Logistic regression revealed the only independent predictors of spontaneous preterm birth <35 weeks were further cervical length shortening (adjusted odds ratio (aOR) 5.73; 95% confidence interval (CI) 1.31 to 24.43) and gestational age at short cervical length (aOR 0.95; 95% CI 0.91 to 0.99). CONCLUSION: Further cervical length shortening in asymptomatic high-risk women with a short cervical length is an important independent predictor of spontaneous preterm birth <35 weeks and perinatal morbidity.

Live-cell imaging of aquaporin-4 diffusion and interactions in orthogonal arrays of particles.

Orthogonal arrays of particles (OAPs) have been visualized for many years by freeze-fracture electron microscopy. Our laboratory discovered that aquaporin-4 (AQP4) is the protein responsible for OAP formation by demonstrating OAPs in AQP4-transfected cells and absence of OAPs in AQP4 knockout mice. We recently developed live-cell, single-molecule imaging methods to study AQP4 diffusion and interactions in OAPs. The methods include single particle tracking of quantum-dot labeled AQP4, and total internal reflection fluorescence microscopy of green fluorescent protein (GFP) and small fluorophore-labeled AQP4. The full-length (M1) form of AQP4 diffuses freely in membranes and does not form OAPs, whereas the shorter (M23) form of AQP4 forms OAPs and is nearly immobile. Analysis of a series of AQP4 truncations, point mutants and chimeras revealed that OAP formation by AQP4-M23 is stabilized by hydrophobic tetramer-tetramer interactions involving N-terminus residues, and that absence of OAPs in AQP4-M1 results from blocking of this interaction by residues just upstream from Met23. These biophysical methods are being extended to identify the cellular site of AQP4 assembly, AQP4 isoform interactions, OAP size and dynamics, and the determinants of regulated OAP assembly.

Selection for low erucic acid and genetic mapping of loci affecting the accumulation of very long-chain fatty acids in meadowfoam seed storage lipids.

Erucic acid (22:1(13)) has been identified as an anti-nutritional compound in meadowfoam (Limnanthes alba) and other oilseeds in the Brassicales, a classification which has necessitated the development of low erucic acid cultivars for human consumption. The erucic acid concentrations of meadowfoam wild types (8%-24%) surpass industry standards for human consumption (

Use of transvaginal ultrasonography to predict preterm birth in women with a history of preterm birth.

OBJECTIVE: To investigate whether cervical length measured by transvaginal ultrasonography predicts spontaneous preterm birth at < 35 weeks' gestation in women with a history of spontaneous preterm birth, stratified by spontaneous preterm birth history subtype (preterm premature rupture of membranes (PPROM) or preterm labor with intact membranes at onset of labor). METHODS: This retrospective cohort study included women with a history of spontaneous preterm birth that were subsequently pregnant with singleton gestations, compared with a low-risk control group. Transvaginal ultrasonographic cervical lengths were measured at 24 to 30 weeks of gestation. The primary outcome was spontaneous preterm birth at < 35 weeks. Secondary outcomes included spontaneous preterm birth at < 37 weeks and < 34 weeks, low birth weight, Cesarean delivery and perinatal morbidity and mortality. Multiple logistic regression analysis was used to control for potential confounders and calculate odds ratios and 95% confidence intervals. Receiver-operating characteristics (ROC) curves were used to determine the best cut-off for transvaginal ultrasound cervical length in predicting spontaneous preterm birth at < 35 weeks. RESULTS: Women with a history of spontaneous preterm birth with intact membranes at onset of labor (n = 42) had a shorter cervical length (3.28 cm) than women with a history of spontaneous preterm birth with PPROM at onset of labor (n = 48, cervical length 3.77 cm; P = 0.019), and both subgroups had shorter cervical lengths than the low-risk control group (n = 103, cervical length 4.30 cm; P < 0.0001). Both subgroups were associated with spontaneous preterm birth at < 35 weeks, < 37 weeks, < 34 weeks and birth weight < 2500 g. ROC curves determined that the best cut-off for cervical length to predict spontaneous preterm birth at < 35 weeks was 3.0 cm. By multiple logistic regression analysis, the only independent predictors of spontaneous preterm birth at < 35 weeks were cervical length < 3.0 cm, a history of spontaneous preterm birth and antepartum bleeding in the current pregnancy. In women with a history of spontaneous preterm birth, a cervical length as measured by transvaginal ultrasonography of < 3.0 cm had a sensitivity of 63.6%, specificity of 77.2%, positive predictive value of 28.0% and negative predictive value of 93.8%, for preterm birth at < 35 weeks. CONCLUSION: Women with a history of spontaneous preterm birth with preterm labor and intact membranes at the onset of labor have shorter cervices than women with a history of spontaneous preterm birth and PPROM at the onset of labor, and both groups have shorter cervices than a low-risk control group. Both groups of women with a history of spontaneous preterm birth have an increased risk of recurrent spontaneous preterm birth at < 35 weeks, and this is predicted by a transvaginal ultrasound cervical length of < 3.0 cm.

Transvaginal sonographic measurement of cervical length to predict preterm birth in asymptomatic women at increased risk: a systematic review.

OBJECTIVES: To estimate the ability of cervical length measured by transvaginal ultrasonography in asymptomatic high-risk women to predict spontaneous preterm birth. METHODS: MEDLINE, PubMed, EMBASE and the Cochrane Library were searched for articles published in any language between January 1980 and July 2006, using the keywords 'transvaginal ultrasonography' or ('cervix' and ('ultrasound' or 'ultrasonography' or 'sonography')); and ('preterm' or 'premature') and ('delivery' or 'labour/labor' or 'birth'), identifying cohort studies evaluating transvaginal ultrasonographic cervical length measurement in predicting preterm birth in asymptomatic women who were considered at increased risk (because of a history of spontaneous preterm birth, uterine anomalies or excisional cervical procedures), with intact membranes and singleton gestations. The primary analysis included all studies meeting the inclusion criteria. Secondary analyses were also performed specifically for (1) women with a history of spontaneous preterm birth; (2) those who had undergone an excisional cervical procedure; and (3) those with uterine anomalies. RESULTS: Fourteen of 322 articles identified (involving 2258 women) met the criteria for systematic review. Cervical length measured by transvaginal ultrasonography predicted spontaneous preterm birth. The shorter the cervical length cut-off the higher the positive likelihood ratio (LR). The most common cervical length cut-off was < 25 mm. Using this cut-off to predict spontaneous preterm birth at < 35 weeks, transvaginal ultrasonography at < 20 weeks' gestation revealed LR+ = 4.31 (95% CI, 3.08-6.01); at 20-24 weeks, LR+ = 2.78 (95% CI, 2.22-3.49); and at > 24 weeks, LR+ = 4.01 (95% CI, 2.53-6.34). In women with a history of spontaneous preterm birth (six studies involving 663 women) cervical length at < 20 weeks revealed LR+ = 11.30 (95% CI, 3.59-35.57) and at 20-24 weeks LR+ = 2.86 (95% CI, 2.12-3.87), but there were limited data on the use of cervical length of more than 24 weeks in this group (one study involving 42 women). In women who had had excisional cervical procedures, two studies presented data on cervical length (one at < 24 weeks and one at > 24 weeks), finding cervical length at < 24 weeks to be predictive of spontaneous preterm birth at < 35 weeks (LR+ = 2.91, 95% CI, 1.69-5.01). One study (of 64 women) evaluated cervical length in women with uterine anomalies, finding it predictive of spontaneous preterm birth at < 35 weeks (LR+ = 8.14, 95% CI, 3.12-21.25). CONCLUSION: Cervical length measured by transvaginal ultrasonography in asymptomatic high-risk women predicts spontaneous preterm birth at < 35 weeks. Further research may be warranted to evaluate the use of transvaginal ultrasonography after 24 weeks' gestation in women with a history of spontaneous preterm birth, and in women with uterine anomalies.

Misoprostol compared with prostaglandin E2 for labour induction in women at term with intact membranes and unfavourable cervix: a systematic review.

BACKGROUND: Misoprostol is a commonly used prostaglandin to induce labour. A potential risk of induction, however, is caesarean delivery, especially in women with an unfavourable cervix. OBJECTIVES: To evaluate the use of misoprostol, compared with prostaglandin E2 (PgE2), for labour induction in women at term with an unfavourable cervix and intact membranes. SEARCH STRATEGY: PubMed, Medline, EMBASE and the Cochrane Library were searched for articles published in any language from January 1987 to December 2005, using the keywords 'misoprostol', 'labour/labor' and 'induction'. SELECTION CRITERIA: We identified randomised trials of women at term (> or =37 weeks of gestation) with intact membranes and unfavourable cervix, undergoing labour induction with misoprostol, orally, vaginally, sublingually or buccally, compared with PgE2 vaginally or intracervically. DATA COLLECTION AND ANALYSIS: Caesarean delivery was the primary outcome, with tachysystole and hyperstimulation as secondary outcomes. The primary analysis compared any misoprostol with any PgE2 for all women, with a subgroup analysis for nulliparous women. Secondary analyses compared different routes and doses of misoprostol (oral or vaginal and 25 microgram or >25 microgram) and PgE2 (intracervical or vaginal). Relative risks (RR) and 95% confidence intervals (CI) were calculated using random effects models. Main results Fourteen of 611 articles identified met the criteria for systematic review, with three providing information for nulliparous women. There was no difference in the risk of caesarean delivery between misoprostol and PgE2 groups (RR = 0.99, 95% CI = 0.83-1.17). Any misoprostol was associated with higher risks of tachysystole and hyperstimulation compared with any PgE2 (RR = 1.86, 95% CI = 1.01-3.43 and RR = 3.71, 95% CI = 2.00-6.88, respectively). There was a higher rate of vaginal delivery within 24 hours among all vaginal deliveries with any misoprostol compared with any PgE2 (RR = 1.14, 95% CI = 1.00-1.31), and among all deliveries, a lower rate of oxytocin use (RR = 0.71, 95% CI = 0.60-0.85) but a trend towards increased meconium staining was observed (RR = 1.22, 95% CI = 0.96-1.55). The use of misoprostol at starting dosages >25 microgram had similar findings to the primary analysis. Studies of lower misoprostol dosing (starting dose of 25 microgram) did not show any differences in the outcomes of interest, but the sample size of this secondary analysis was small (304 women, 155 receiving misoprostol). AUTHOR'S CONCLUSIONS: Although misoprostol in women at term with an unfavourable cervix and intact membranes was more effective than PgE2 in achieving vaginal delivery within 24 hours, misoprostol does not reduce the rate of caesarean delivery either in all women or in the subgroup of nulliparous women, and it increases the rates of tachysystole and hyperstimulation. Further studies of misoprostol using a starting dose of 25 microgram may be warranted.

Predictors of successful labor induction with oral or vaginal misoprostol.

OBJECTIVE: To identify independent predictors of successful labor induction with oral or vaginal misoprostol. METHODS: Women enrolled in four previous randomized trials involving oral or vaginal misoprostol for cervical ripening and labor induction were included in the present cohort study, with dosing of 25-50 microg every 4 to 6 h vaginally (n = 574) or 50 microg every 4 h orally (n = 207). Multiple logistic regression was performed to identify factors independently associated with successful labor induction -- defined as vaginal delivery within 12 h, vaginal delivery within 24 h and spontaneous vaginal delivery. Predictors of Cesarean birth and the need for only one dose of misoprostol were also identified. Variables included in the models were maternal age, weight, height, parity, gravidity, membrane status, route of misoprostol, gestational age, birth weight, and Bishop score and its individual components. RESULTS: Maternal age, height, weight, parity, birth weight, dilatation, effacement and cervical station were associated with vaginal delivery within 24 h of induction. Maternal age, height, weight, nulliparity, birth weight and route of misoprostol were associated with Cesarean birth, with oral misoprostol being associated with a lower rate of Cesarean birth. The need for only one dose of misoprostol was predicted by maternal height, weight, parity, gestational age, Bishop score and route of misoprostol. CONCLUSION: Characteristics of the woman (height, weight, parity), the fetus (birth weight) and some of the individual components of the Bishop score, were associated with successful labor induction, with oral misoprostol being associated with a lower rate of Cesarean birth.

The development of a genetic map for meadowfoam comprised of amplified fragment length polymorphisms.

Limnanthes alba Benth. (meadowfoam), a diploid ( x=5) winter annual, produces novel very long-chain seed oils (C(20) and C(22)) with less than 2% saturated fatty acids. The first genetic map of meadowfoam, a recently domesticated species, is described herein. Two phenotypically diverse inbred lines, OMF40-11 ( L. alba ssp. alba) and OMF64 ( L. alba ssp. versicolor), were screened for amplified fragment length polymorphisms (AFLPs) using 16 primer combinations. Twenty three percent of the AFLP bands (415 out of 1,801) were polymorphic between OMF40-11 and OMF64. One hundred (OMF40-11xOMF64)xOMF64 BC(1) progeny were genotyped for 107 polymorphic AFLP markers produced by nine AFLP primer combinations. One hundred and three AFLP loci amalgamated into five linkage groups with 14 to 28 loci per linkage group (four loci segregated independently). The map was 698.5-cM long with a mean interlocus spacing of 6.7 cM and no dense clustering of loci. The segregation ratios for 25 loci (23.2%) were significantly distorted. Twenty one of the distorted loci (84%) had an excess of L. alba ssp. versicolor (recurrent parent) alleles. The distorted loci, apart from one locus on linkage group 4, were distally clustered on both ends of linkage groups 1, 4 and 5. The development of the map was facilitated by the small chromosome number, an abundance of restriction site polymorphisms between the two subspecies (23%), and a high multiplex ratio of the AFLP markers (112 per primer combination).

Peptide mimics of SNARE transmembrane segments drive membrane fusion depending on their conformational plasticity.

SNARE proteins are essential for different types of intracellular membrane fusion. Whereas interaction between their cytoplasmic domains is held responsible for establishing membrane proximity, the role of the transmembrane segments in the fusion process is currently not clear. Here, we used an in vitro approach based on lipid mixing and electron microscopy to examine a potential fusogenic activity of the transmembrane segments. We show that the presence of synthetic peptides representing the transmembrane segments of the presynaptic soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) synaptobrevin II (also referred to as VAMP II) or syntaxin 1A, but not of an unrelated control peptide, in liposomal membranes drives their fusion. Liposome aggregation by millimolar Ca(2+) concentrations strongly potentiated the effect of the peptides; this indicates that juxtaposition of the bilayers favours their fusion in the absence of the cytoplasmic SNARE domains. Peptide-driven fusion is reminiscent of natural membrane fusion, since it was suppressed by lysolipid and involved both bilayer leaflets. This suggests transient presence of a hemifusion intermediate followed by complete membrane merger. Structural studies of the peptides in lipid bilayers performed by Fourier transform infrared spectroscopy indicated mixtures of alpha-helical and beta-sheet conformations. In isotropic solution, circular dichroism spectroscopy showed the peptides to exist in a concentration-dependent equilibrium of alpha-helical and beta-sheet structures. Interestingly, the fusogenic activity decreased with increasing stability of the alpha-helical solution structure for a panel of variant peptides. Thus, structural plasticity of transmembrane segments may be important for SNARE protein function at a late step in membrane fusion.

Transvaginal ultrasound and digital examination in predicting successful labor induction.

OBJECTIVE: To compare transvaginal ultrasound and digital cervical examination in predicting successful induction in post-term pregnancy. METHODS: Transvaginal ultrasound and digital vaginal examinations were performed on 122 women at 41 or more weeks' gestation, immediately before labor induction. Ultrasound assessments of cervical length, dilatation, and presence of funneling were compared with the components of the Bishop score. The primary outcome was the rate of vaginal delivery. Secondary outcomes assessed included the rates of active labor in 12 hours, vaginal delivery in 12 and 24 hours, mean duration of latent phase, and induction to vaginal delivery interval. Linear and multiple logistic regression models were generated to identify factors independently associated with successful induction. RESULTS: No ultrasound characteristic predicted primary or secondary outcomes. Bishop score (odds ratio [OR] 2.98, 95% confidence interval [CI] 1.71, 5.20), cervical position (OR 4.35, 95% CI 1.41, 12.50), and maternal age (OR 1.15, 95% CI 1.01, 1.30) independently predicted vaginal delivery. Maternal weight (OR 0.96, 95% CI 0.94, 0.98), cervical dilatation (OR 6.08, 95% CI 1.70, 21.68), and effacement (OR 2.34, 95% CI 1.16, 4.73) independently predicted active labor in 12 hours. Independent predictors of vaginal delivery in 12 hours were induction method (P <.001), cervical dilatation (OR 11.16, 95% CI 3.17, 39.29), gravidity (OR 2.06, 95% CI 1.13, 3.77), and maternal weight (OR 0.96, 95% CI 0.93, 0.99). Cervical effacement (OR 2.70, 95% CI 1.59, 4.57) and parity (OR 7.10, 95% CI 2.22, 22.72) independently predicted vaginal delivery in 24 hours. Maternal weight, cervical position, and cervical dilatation were independently associated with latent phase labor duration. Factors independently associated with length of induction to delivery interval were parity, cervical effacement, and maternal weight. CONCLUSION: Transvaginal ultrasound does not predict successful labor induction in post-term pregnancy as well as digital cervical examination.

Excessive uterine activity accompanying induced labor.

OBJECTIVE: To estimate the incidence and timing of excessive uterine activity accompanying induction of labor with misoprostol using different routes (oral or vaginal) and forms (intact tablet or crushed) and to compare these with dinoprostone gel, oxytocin, and spontaneous labor. METHODS: This retrospective cohort study included 519 women at term who had labor induced and 86 women at term in spontaneous labor. Induction agents included misoprostol, dinoprostone, or oxytocin. Fetal heart rate and uterine activity tracings were analyzed independently by three maternal-fetal medicine physicians. The diagnosis of tachysystole or hyperstimulation required the agreement of two or more reviewers. RESULTS: The incidence of tachysystole was highest with misoprostol administered by vaginal tablet (misoprostol vaginal tablet 50 microg every 4 hours, 48.6%; vaginal tablet crushed 50 microg and suspended in hydroxyethyl gel every 4 hours, 30.7%, P =.009; oral tablet 50 microg every 4 hours, 22.2%, P =.001; oral tablet crushed 50 microg every 4 hours, 15.5%, P <.001; dinoprostone gel, 33.0%, P =.022; intravenous oxytocin, 30.2%, P =.027; and spontaneous onset of labor, 23.3%, P <.001). Hyperstimulation occurred more often with dinoprostone gel (16.5%) than with other forms of induction or spontaneous labor. Hyperstimulation occurred significantly more often with vaginal misoprostol crushed tablet (7.9%) and vaginal misoprostol intact tablet (7.6%) than with crushed oral misoprostol (1.0%) (P =.016 and.018, respectively). There was a shorter time to tachysystole with increasing doses of vaginal misoprostol tablet (P =.01). CONCLUSION: The incidence of tachysystole and hyperstimulation, and time to tachysystole, varied depending on the route and form of misoprostol given.

Quality improvement efforts in oncology: are we ready to begin?

Large variations in the quality of cancer care are a matter of concern in the United States. Despite spending over 15% of our GNP on health care, more than any other country in the world, some cancer patients face significant risks of dying from their treatment precisely because of their choice of physician. The Institute of Medicine has reported that variations in the quality of cancer are large, and that low-experienced providers are more likely to provide a lower quality of medical care. Increased pressures to contain costs have led to concern that the quality and outcomes of cancer care may only worsen. One reaction to this situation is a greater reliance on "report cards." In an effort to address both quality and cost issues, providers are looking outside the health care sector for guidance for more acceptable alternatives to report cards, which are often viewed as punitive. The approach that they most often have selected recently is termed continuous quality improvement (CQI) or total quality management (TQM). In this article, we describe the potential benefits and drawbacks of CQI efforts in oncology, review experiences with four different CQI cancer programs, and make recommendations about future CQI efforts.

Rapid compression transforms interfacial monolayers of pulmonary surfactant.

Films of pulmonary surfactant in the lung are metastable at surface pressures well above the equilibrium spreading pressure of 45 mN/m but commonly collapse at that pressure when compressed in vitro. The studies reported here determined the effect of compression rate on the ability of monolayers containing extracted calf surfactant at 37 degrees C to maintain very high surface pressures on the continuous interface of a captive bubble. Increasing the rate from 2 A(2)/phospholipid/min (i.e., 3% of (initial area at 40 mN/m)/min) to 23%/s produced only transient increases to 48 mN/m. Above a threshold rate of 32%/s, however, surface pressures reached > 68 mN/m. After the rapid compression, static films maintained surface pressures within +/- 1 mN/m both at these maximum values and at lower pressures following expansion at < 5%/min to > or = 45 mN/m. Experiments with dimyristoyl phosphatidylcholine at 37 degrees C produced similar results. These findings indicate that compression at rates comparable to values in the lungs can transform at least some phospholipid monolayers from a form that collapses readily at the equilibrium spreading pressure to one that is metastable for prolonged periods at higher pressures. Our results also suggest that transformation of surfactant films can occur without refinement of their composition.