Leaf cuticle analyses: implications for the existence of cutan/non-ester cutin and its biosynthetic origin.

BACKGROUND AND AIMS: The cuticle of a limited number of plant species contains cutan, a chemically highly resistant biopolymer. As yet, the biosynthesis of cutan is not fully understood. Attempting to further unravel the origin of cutan, we analysed the chemical composition of enzymatically isolated cuticular membranes of Agave americana leaves. METHODS: Cuticular waxes were extracted with organic solvents. Subsequently, the dewaxed cuticular membrane was depolymerized by acid-catalysed transesterification yielding cutin monomers and cutan, a non-hydrolysable, cuticular membrane residue. The cutan matrix was analysed by thermal extraction, flash pyrolysis and thermally assisted hydrolysis and methylation to elucidate the monomeric composition and deduce a putative biosynthetic origin. KEY RESULTS: According to gas chromatography-mass spectrometry analyses, the cuticular waxes of A. americana contained primarily very-long-chain alkanoic acids and primary alkanols dominated by C32, whereas the cutin biopolyester of A. americana mainly consisted of 9,10-epoxy ω-hydroxy and 9,10,ω-trihydroxy C18 alkanoic acids. The main aliphatic cutan monomers were alkanoic acids, primary alkanols, ω-hydroxy alkanoic acids and alkane-α,ω-diols ranging predominantly from C28 to C34 and maximizing at C32. Minor contributions of benzene-1,3,5-triol and derivatives suggested that these aromatic moieties form the polymeric core of cutan, to which the aliphatic moieties are linked via ester and possibly ether bonds. CONCLUSIONS: High similarity of aliphatic moieties in the cutan and the cuticular wax component indicated a common biosynthetic origin. In order to exclude species-specific peculiarities of A. americana and to place our results in a broader context, cuticular waxes, cutin and cutan of Clivia miniata, Ficus elastica and Prunus laurocerasus leaves were also investigated. A detailed comparison showed compositional and structural differences, indicated that cutan was only found in leaves of perennial evergreen A. americana and C. miniata, and made clear that the phenomenon of cutan is possibly less present in plant species than suggested in the literature.

Cranberries after pelvic floor surgery for urinary tract infection prophylaxis: A randomized controlled trial.

AIMS: Urinary tract infection (UTI) is a common complication after pelvic floor surgery. Antibiotics as prophylaxis may reduce the prevalence of UTI's by 50%, but bacterial resistance may be a large disadvantage, necessitating the search for other possible prophylactic options. Recent research found a 50% reduction in the rate of UTI's with the use of cranberry capsules after elective gynecologic surgery, suggesting that cranberry capsules may serve as a good prophylaxis. The aim of this study was to assess whether perioperative cranberry prophylaxis reduces the risk of clinical overt UTI after elective pelvic floor surgery with indwelling catheter. METHODS: We conducted a single-center randomized, double-blind, placebo-controlled trial. Women were given cranberry capsules twice daily or identical placebo for 6 weeks, starting the day before surgery. The main endpoint of the trial was the incidence of UTI within 6 weeks after surgery, defined as clinical diagnosis and treatment of UTI by the medical doctor. Analyses were performed with the intention to treat. RESULTS: Two hundred ten participants were included, 105 in each arm. There was no significant difference in the prevalence of UTI between the cranberry arm (n = 13, 12.4%) and the placebo arm (n = 21, 20.0%; P = .13), but the prevalence in both arms was lower than anticipated. CONCLUSIONS: This trial shows no beneficial effect of adequately dosed cranberry prophylaxis in women undergoing pelvic floor surgery, although such effect cannot be ruled out in settings with a higher prevalence of UTI's.

Induction of labour at term with oral misoprostol versus a Foley catheter (PROBAAT-II): a multicentre randomised controlled non-inferiority trial.

BACKGROUND: Labour is induced in 20-30% of all pregnancies. In women with an unfavourable cervix, both oral misoprostol and Foley catheter are equally effective compared with dinoprostone in establishing vaginal birth, but each has a better safety profile. We did a trial to directly compare oral misoprostol with Foley catheter alone. METHODS: We did an open-label randomised non-inferiority trial in 29 hospitals in the Netherlands. Women with a term singleton pregnancy in cephalic presentation, an unfavourable cervix, intact membranes, and without a previous caesarean section who were scheduled for induction of labour were randomly allocated to cervical ripening with 50 µg oral misoprostol once every 4 h or to a 30 mL transcervical Foley catheter. The primary outcome was a composite of asphyxia (pH ≤7·05 or 5-min Apgar score <7) or post-partum haemorrhage (≥1000 mL). The non-inferiority margin was 5%. The trial is registered with the Netherlands Trial Register, NTR3466. FINDINGS: Between July, 2012, and October, 2013, we randomly assigned 932 women to oral misoprostol and 927 women to Foley catheter. The composite primary outcome occurred in 113 (12·2%) of 924 participants in the misoprostol group versus 106 (11·5%) of 921 in the Foley catheter group (adjusted relative risk 1·06, 90% CI 0·86-1·31). Caesarean section occurred in 155 (16·8%) women versus 185 (20·1%; relative risk 0·84, 95% CI 0·69-1·02, p=0·067). 27 adverse events were reported in the misoprostol group versus 25 in the Foley catheter group. None were directly related to the study procedure. INTERPRETATION: In women with an unfavourable cervix at term, induction of labour with oral misoprostol and Foley catheter has similar safety and effectiveness. FUNDING: FondsNutsOhra.

Choice of mode of delivery in a subsequent pregnancy after OASI: a survey among Dutch gynecologists.

INTRODUCTION AND HYPOTHESIS: National and international guidelines do not provide clear recommendations on the mode of delivery in a subsequent pregnancy after obstetric anal sphincter injury (OASI). The aim of this study was to investigate the opinion of gynecologists in The Netherlands on this choice and the extent to which this choice is affected by the gynecologist's characteristics. METHODS: Of 973 gynecologists sent a questionnaire seeking their opinion on the mode of delivery in 16 different case descriptions, 234 (24%) responded. Factors influencing the opinion of the respondents on the mode of delivery, the presence of anal symptoms, the degree of OASI and the characteristics of the respondents were analyzed by univariate and multivariate logistic regression analysis. RESULTS: Recommendations on the mode of delivery in a subsequent pregnancy after OASI showed considerable variation. The recommendations depended on (previous) symptoms and the degree of OASI. For gynecologists who based their recommendations on endoanal ultrasonography outcomes (7-20% depending on the case), the degree of OASI and severity of (previous) symptoms were less important. Gynecologists basing their recommendations on endoanal ultrasonography recommended a primary cesarean section less often. Gynecologist's characteristics (including years of experience, type of hospital and subspecialty) had a small effect on their recommendations on the mode of delivery. CONCLUSIONS: Due to lack of evidence, recommendations of gynecologists in The Netherlands on the mode of delivery in a subsequent pregnancy after OASI vary widely and depend on (previous) symptoms and the degree of OASI. Gynecologists who based their recommendations on endoanal ultrasonography outcomes recommended cesarean section less often.

Women's Experiences with and Preference for Induction of Labor with Oral Misoprostol or Foley Catheter at Term.

Objective We assessed experience and preferences among term women undergoing induction of labor with oral misoprostol or Foley catheter. Study Design In 18 of the 29 participating hospitals in the PROBAAT-II trial, women were asked to complete a questionnaire within 24 hours after delivery. We adapted a validated questionnaire about expectancy and experience of labor and asked women whether they would prefer the same method again in a future pregnancy. Results The questionnaire was completed by 502 (72%) of 695 eligible women; 273 (54%) had been randomly allocated to oral misoprostol and 229 (46%) to Foley catheter. Experience of the duration of labor, pain during labor, general satisfaction with labor, and feelings of control and fear related to their expectation were comparable between both the groups. In the oral misoprostol group, 6% of the women would prefer the other method if induction is necessary in future pregnancy, versus 12% in the Foley catheter group (risk ratio: 0.70; 95% confidence interval: 0.55-0.90; p = 0.02). Conclusion Women's experiences of labor after induction with oral misoprostol or Foley catheter are comparable. However, women in the Foley catheter group prefer more often to choose a different method for future inductions.

Management of late-preterm premature rupture of membranes: the PPROMEXIL-2 trial.

OBJECTIVE: The evidence for the management of near term prelabor rupture of membranes is poor. From January 2007 until September 2009, we performed the PPROM Expectant Management versus Induction of Labor (PPROMEXIL) trial. In this trial, we showed that in women with preterm prelabor rupture of membranes (PPROM), the incidence of neonatal sepsis was low, and the induction of labor (IoL) did not reduce this risk. Because the PPROMEXIL trial was underpowered and because of a lower-than-expected incidence of neonatal sepsis, we performed a second trial (PPROMEXIL-2), aiming to randomize 200 patients to improve the evidence in near-term PPROM. STUDY DESIGN: In a nationwide multicenter study, nonlaboring women with PPROM between 34 and 37 weeks' gestational age were eligible for inclusion. Patients were randomized to IoL or expectant management (EM). The primary outcome measure was neonatal sepsis. RESULTS: From December 2009 until January 2011, we randomized 100 women to IoL and 95 to EM. Neonatal sepsis was seen in 3 neonates (3.0%) in the IoL-group versus 4 neonates (4.1%) in the EM group (relative risk, 0.74; 95% confidence interval, 0.17-3.2). One of the sepsis cases in the IoL group resulted in neonatal death because of asphyxia. There were no significant differences in secondary outcomes. CONCLUSION: The risk of neonatal sepsis after PPROM near term is low. Induction of labor does not reduce this risk.

Episodic fresh surface waters in the Eocene Arctic Ocean.

It has been suggested, on the basis of modern hydrology and fully coupled palaeoclimate simulations, that the warm greenhouse conditions that characterized the early Palaeogene period (55-45 Myr ago) probably induced an intensified hydrological cycle with precipitation exceeding evaporation at high latitudes. Little field evidence, however, has been available to constrain oceanic conditions in the Arctic during this period. Here we analyse Palaeogene sediments obtained during the Arctic Coring Expedition, showing that large quantities of the free-floating fern Azolla grew and reproduced in the Arctic Ocean by the onset of the middle Eocene epoch (approximately 50 Myr ago). The Azolla and accompanying abundant freshwater organic and siliceous microfossils indicate an episodic freshening of Arctic surface waters during an approximately 800,000-year interval. The abundant remains of Azolla that characterize basal middle Eocene marine deposits of all Nordic seas probably represent transported assemblages resulting from freshwater spills from the Arctic Ocean that reached as far south as the North Sea. The termination of the Azolla phase in the Arctic coincides with a local sea surface temperature rise from approximately 10 degrees C to 13 degrees C, pointing to simultaneous increases in salt and heat supply owing to the influx of waters from adjacent oceans. We suggest that onset and termination of the Azolla phase depended on the degree of oceanic exchange between Arctic Ocean and adjacent seas.

Quantitative analysis of diverse sporomorph-derived sporopollenins.

Over the years studies on sporopollenin have reported a wide variety of structures. However, the methods and techniques used to elucidate sporopollenin structures are highly diverse so that much is still unclear with respect to the nature and structural diversity of sporopollenins. In order to investigate the structural diversity in sporopollenin between different taxa, extant sporomorphs of ten different species ranging from a mushroom to a cycad were examined using a relatively simple and fast analytical procedure. Sporomorphs, before and after saponification, were analysed for sporopollenin composition by Thermally assisted Hydrolysis and Methylation (THM) using [13C]tetramethylammonium hydroxide ([13C]TMAH). The sporomorp chemical composition differed markedly between the groups of organisms analysed. Moreover, we not only identified the nature and relative quantities of the well-known sporopollenin constituents p-coumaric acid and ferulic acid but also many other phenolic moieties, such as caffeic acid, which appeared to be the most abundant phenolic constituent in spores of Equisetum palustre, Salvinia molesta, Cyrtomium falcatum and Anemia phyllitidis. Within the two Equisetum species analysed as well as in the closely related Azolla and Salvinia species the same suite of phenolic constituents were observed, but their relative distribution varied largely. We thus demonstrate the existence of a high structural diversity, both qualitatively and quantitatively in sporopollenins enabling future studies related to the evolution, phylogeny and (palaeo)environment of sporopollenin-producing organisms. Furthermore, a better knowledge of sporopollenin and its structural variety is of relevance to the rapidly growing application of spores and pollen as a drug delivery agent in medicine.

Diel variations in carbon metabolism by green nonsulfur-like bacteria in alkaline siliceous hot spring microbial mats from Yellowstone National Park.

Green nonsulfur-like bacteria (GNSLB) in hot spring microbial mats are thought to be mainly photoheterotrophic, using cyanobacterial metabolites as carbon sources. However, the stable carbon isotopic composition of typical Chloroflexus and Roseiflexus lipids suggests photoautotrophic metabolism of GNSLB. One possible explanation for this apparent discrepancy might be that GNSLB fix inorganic carbon only during certain times of the day. In order to study temporal variability in carbon metabolism by GNSLB, labeling experiments with [13C]bicarbonate, [14C]bicarbonate, and [13C]acetate were performed during different times of the day. [14C]bicarbonate labeling indicated that during the morning, incorporation of label was light dependent and that both cyanobacteria and GNSLB were involved in bicarbonate uptake. 13C-labeling experiments indicated that during the morning, GNSLB incorporated labeled bicarbonate at least to the same degree as cyanobacteria. The incorporation of [13C]bicarbonate into specific lipids could be stimulated by the addition of sulfide or hydrogen, which both were present in the morning photic zone. The results suggest that GNSLB have the potential for photoautotrophic metabolism during low-light periods. In high-light periods, inorganic carbon was incorporated primarily into Cyanobacteria-specific lipids. The results of a pulse-labeling experiment were consistent with overnight transfer of label to GNSLB, which could be interrupted by the addition of unlabeled acetate and glycolate. In addition, we observed direct incorporation of [13C]acetate into GNSLB lipids in the morning. This suggests that GNSLB also have a potential for photoheterotrophy in situ.

Compound-specific isotopic fractionation patterns suggest different carbon metabolisms among Chloroflexus-like bacteria in hot-spring microbial mats.

Stable carbon isotope fractionations between dissolved inorganic carbon and lipid biomarkers suggest photoautotrophy by Chloroflexus-like organisms in sulfidic and nonsulfidic Yellowstone hot springs. Where co-occurring, cyanobacteria appear to cross-feed Chloroflexus-like organisms supporting photoheterotrophy as well, although the relatively small 13C fractionation associated with cyanobacterial sugar biosynthesis may sometimes obscure this process.