Genotype-outcome correlations in pediatric AML: the impact of a monosomal karyotype in trial AML-BFM 2004.

We conducted a cytogenetic analysis of 642 children with de novo acute myeloid leukemia (AML) treated on the AML-Berlin-Frankfurt-Münster (BFM) 04 protocol to determine the prognostic value of specific chromosomal aberrations including monosomal (MK+), complex (CK+) and hypodiploid (HK+) karyotypes, individually and in combination. Multivariate regression analysis identified in particular MK+ (n=22) as a new independent risk factor for poor event-free survival (EFS 23±9% vs 53±2% for all other patients, P=0.0003), even after exclusion of four patients with monosomy 7 (EFS 28±11%, P=0.0081). CK+ patients without MK had a better prognosis (n=47, EFS 47±8%, P=0.46) than those with MK+ (n=12, EFS 25±13%, P=0.024). HK+ (n=37, EFS 44±8% for total cohort, P=0.3) influenced outcome only when t(8;21) patients were excluded (remaining n=16, EFS 9±8%, P<0.0001). An extremely poor outcome was observed for MK+/HK+ patients (n=10, EFS 10±10%, P<0.0001). Finally, isolated trisomy 8 was also associated with low EFS (n=16, EFS 25±11%, P=0.0091). In conclusion, monosomal karyotype is a strong and independent predictor for high-risk pediatric AML. In addition, isolated trisomy 8 and hypodiploidy without t(8;21) coincide with dismal outcome. These results have important implications for risk stratification and should be further validated in independent pediatric cohorts.

Management of urologic complications in renal transplantation: a single-center experience.

INTRODUCTION: Ureterovesical complications subsequent to renal transplantation are associated with a high morbidity leading to graft loss or even death. In the present study, the management of these complications by using interventional and surgical procedures (native pyeloureterostomy [NPUS]/ureteroureterostomy [NUU] vs ureteroneocystostomy [UNC]) was evaluated retrospectively. PATIENTS AND METHODS: Between 1994 and 2012, a total of 780 kidney transplantations (690 deceased and 90 living donors) were performed at our institution. Demographic, clinical, and laboratory data from patients with urologic complications were analyzed and compared. RESULTS: Fifty patients (6.4%) exhibited ureterovesical complications, and 18 patients (36%) were operated on immediately. In 32 (64%) of 50 patients, an interventional procedure was initially performed, with 21 patients (66%) undergoing operation due to therapy failure. NPUS/NUU and UNC were performed in 26 (66.6%) and 13 (33.3%) patients, respectively. Indications for an operation were ureteral stenosis in 12 patients (30.8%), ureteral necrosis and urine leakage in 19 patients (48.7%), and symptomatic vesicoureteral reflux in 8 patients (20.5%). Long-term results were comparable between all groups. CONCLUSIONS: Surgical revision of ureteral complications should be the standard therapy. NPUS/NUU, UNC, and the successful interventional procedures did not differ significantly in terms of long-term results.

Improved generation of patient-specific induced pluripotent stem cells using a chemically-defined and matrigel-based approach.

Reprogramming of somatic cells into patient-specific pluripotent analogues of human embryonic stem cells (ESCs) emerges as a prospective therapeutic angle in molecular medicine and a tool for basic stem cell biology. However, the combination of relative inefficiency and high variability of non-defined culture conditions precluded the use of this technique in a clinical setting and impeded comparability between laboratories. To overcome these obstacles, we sequentially devised a reprogramming protocol using one lentiviral-based polycistronic reprogramming construct, optimized for high co-expression of OCT4, SOX2, KLF4 and MYC in conjunction with small molecule inhibitors of non-permissive signaling cascades, such as transforming growth factor ß (SB431542), MEK/ERK (PD0325901) and Rho-kinase signaling (Thiazovivin), in a defined extracellular environment. Based on human fetal liver fibroblasts we could efficiently derive induced pluripotent stem cells (iPSCs) within 14 days. We attained efficiencies of up to 10.97±1.71% resulting in 79.5- fold increase compared to non-defined reprogramming using four singular vectors. We show that the overall increase of efficiency and temporal kinetics is a combinatorial effect of improved lentiviral vector design, signaling inhibition and definition of extracellular matrix (Matrigel®) and culture medium (mTESR®1). Using this protocol, we could derive iPSCs from patient fibroblasts, which were impermissive to classical reprogramming efforts, and from a patient suffering from familial platelet disorder. Thus, our defined protocol for highly efficient reprogramming to generate patient-specific iPSCs, reflects a big step towards therapeutic and broad scientific application of iPSCs, even in previously unfeasible settings.

Purification and partial characterization of the Pyrococcus horikoshii methylmalonyl-CoA epimerase.

Methylmalonyl-CoA epimerase (MCE) from the hyperthermophilic archaeon, Pyrococcus horikoshii, was expressed at high levels in Escherichia coli, purified, and partially characterized. The P. horikoshii MCE enzyme was a homodimer with an apparent molecular mass of 31,700 Da. The K(m) of the enzyme for methylmalonyl-CoA was 79 microM and the k(cat) was 240 s(-1). The P. horikoshii enzyme was extremely heat-stable and withstood boiling for 60 min without detectable loss in activity.

Characterization of methanogenic and methanotrophic assemblages in landfill samples.

A greater understanding of the tightly linked trophic groups of anaerobic and aerobic bacteria residing in municipal solid waste landfills will increase our ability to control methane emissions and pollutant fate in these environments. To this end, we characterized the composition of methanogenic and methanotrophic bacteria in samples taken from two regions of a municipal solid waste landfill that varied in age. A method combining polymerase chain reaction amplification, restriction fragment length polymorphism analysis and phylogenetic analysis was used for this purpose. 16S rDNA sequence analysis revealed a rich assemblage of methanogens in both samples, including acetoclasts, H2/CO2-users and formate-users in the newer samples and H2/CO2-users and formate-users in the older samples, with closely related genera including Methanoculleus, Methanofollis, Methanosaeta and Methanosarcina. Fewer phylotypes of type 1 methanotrophs were observed relative to type 2 methanotrophs. Most type 1 sequences clustered within a clade related to Methylobacter, whereas type 2 sequences were broadly distributed among clades associated with Methylocystis and Methylosinus species. This genetic characterization tool promises rapid screening of landfill samples for genotypes and, therefore, degradation potentials.

Identification of the human methylmalonyl-CoA racemase gene based on the analysis of prokaryotic gene arrangements. Implications for decoding the human genome.

In this report, we identify the human DL-methylmalonyl-CoA racemase gene by analyzing prokaryotic gene arrangements and extrapolating the information obtained to human genes by homology searches. Sequence similarity searches were used to identify two groups of homologues that were frequently arranged with prokaryotic methylmalonyl-CoA mutase genes, and that were of unknown function. Both gene groups had homologues in the human genome. Because methylmalonyl-CoA mutases are involved in the metabolism of propionyl-CoA, we inferred that conserved neighbors of methylmalonyl-CoA mutase genes and their human homologues were also involved in this process. Subsequent biochemical studies confirmed this inference by showing that the prokaryotic gene PH0272 and its human homologue both encode DL-methylmalonyl-CoA racemases. To our knowledge this is the first report in which the function of a eukaryotic gene was determined based on the analysis of prokaryotic gene arrangements. Importantly, such analyses are rapid and may be generally applicable for the identification of human genes that lack homologues of known function or that have been misidentified on the basis of sequence similarity searches.

Mechanism for the enzymatic formation of 4-(beta-D-ribofuranosyl)aminobenzene 5'-phosphate during the biosynthesis of methanopterin.

A central step in the biosynthesis of the modified folate methanopterin is the condensation of p-aminobenzoic acid (pAB) and 5-phospho-alpha-D-ribosyl-1-pyrophosphate (PRPP) which produce 4-(beta-D-ribofuranosyl)aminobenzene 5'-phosphate (beta-RFA-P) [White, R. H. (1996) Biochemistry 35, 3447-3456]. This reaction, catalyzed by the enzyme beta-RFA-P synthase, is unique among known phosphoribosyltransferases in that a decarboxylation of one of the substrates (pAB) occurs during the reaction and a C-riboside rather than an N-riboside is the product. In this work, the reaction catalyzed by the enzyme from Methanosarcina thermophila is shown to be analogous to other phosphoribosyltransferase reactions in that pyrophosphate is released as a product of the reaction, which is dependent upon magnesium ions. The molecular weight of the enzyme was estimated to be 65 000 using gel filtration chromatography, and the pH optimum was 4.8. Kinetic analysis indicated that the reaction involved a sequential pattern of substrate binding. Benzoic acid and several para-substituted benzoic acids inhibited beta-RFA-P synthase activity, while aniline, 4-aminobenzamide, and the methyl ester of pAB did not, indicating that an ionized carboxylic group plays a role in the binding of pAB. The observation that the enzyme was not inhibited by carbonyl reagents and that 4-hydroxybenzoic acid served as an alternate substrate, producing 4-(beta-D-ribofuranosyl)hydroxybenzene 5'-phosphate as the product, indicated that pyridoxal phosphate was not directly involved in the reaction mechanism. Incubation of the enzyme with PRPP and either pAB or 4-aminothiobenzoic acid in the presence of sodium cyanoborohydride led to the decreased production of beta-RFA-P and the accumulation of a reduced form of the proposed cyclohexadienimine reaction intermediates. These compounds were characterized by their acid-catalyzed decomposition which produces beta-D-ribofuranosylbenzene 5'-phosphate. On the basis of these results, a concerted mechanism is proposed for beta-RFA-P synthase in which an SN1-like reaction produces oxonium ion character at C-1 of PRPP which undergoes an ipso electrophilic aromatic substitution reaction at the carboxylic acid-bound carbon of pAB. Decarboxylation of the resulting cyclohexadienimine intermediate leads to the formation of beta-RFA-P.

Identification of cysteine and arginine residues essential for the phosphotransacetylase from Methanosarcina thermophila.

Phosphotransacetylase catalyzes the following reaction: CoASH + CH3CO2PO3(2-) <==> CH3COSCoA + HPO4(2-) (where CoA is coenzyme A). Based on biochemical characterization of the enzyme from the obligate anaerobe Clostridium kluyveri, a ternary mechanism was proposed in which an unspecified cysteine abstracts a proton from CoASH forming a nucleophilic thiolate anion which attacks acetyl phosphate (J. Henkin and R. H. Abeles, Biochemistry 15:3472-3479, 1976). Heterologous production in Escherichia coli of the phosphotransacetylase from Methanosarcina thermophila, an obligately anaerobic methanoarchaeon, allowed site-specific replacements to identify essential residues. All four cysteines present in the sequence were individually replaced with alanine, and the kinetic constants of the altered enzymes were determined. The results indicated that only C159 is essential for activity; however, replacement with serine resulted in a fully active enzyme. Activity of the unaltered phosphotransacetylase was sensitive to N-ethylmaleimide. Inhibition kinetics of altered enzymes indicated that this sensitivity resulted from modification of C312, which is at the active site but itself is nonessential for catalysis. Five arginines were individually replaced with glutamine. Kinetic analysis of the altered enzymes identified R310 as essential for activity. Of the four nonessential for activity, R87 and R133 appear to be involved in binding CoA.

Reduction of thiocyanate, cyanate, and carbon disulfide by nitrogenase: kinetic characterization and EPR spectroscopic analysis.

Nitrogenase catalyzes the reduction of N2, protons, and a number of alternative substrates that contain C-C, C-N, N-N, and N-O double and triple bonds. Recently it has been shown that nitrogenase also reduces the C==S bond of COS and the C==O bond of CO2. The current work demonstrates that the COS analogs SCN-, CS2, and OCNH are novel substrates for nitrogenase and that the reduction of these substrates produces changes in the electron paramagnetic resonance (EPR) spectrum of nitrogenase, providing insight into the mechanism of substrate reduction by nitrogenase. CH4, HCN, H2S, and NH4+ were detected as products of the nitrogenase-catalyzed reduction of SCN-. CS2 was reduced by nitrogenase to H2S, providing the first demonstration of CS2 reduction catalyzed by a purified enzyme. CO was detected as a product of KOCN reduction by nitrogenase. Interestingly, the Km for KOCN reduction to CO decreased at lower pH values, suggesting that OCNH rather than OCN- was the substrate for nitrogenase. Analysis of the EPR spectra of nitrogenase under turnover conditions in the presence of KOCN, CS2, or KSCN revealed new EPR signals. Signals with g-values corresponding to those reported for CO bound to the iron-molybdenum cofactor of nitrogenase were detected during turnover of nitrogenase in the presence of KOCN. During SCN- and CS2 reduction by nitrogenase, novel EPR inflections were observed that appear to report the interaction between nitrogenase and a bound substrate or a transient intermediate produced during the reduction of SCN- and CS2.

Carbonyl sulfide and carbon dioxide as new substrates, and carbon disulfide as a new inhibitor, of nitrogenase.

Nitrogenase is the metalloenzyme responsible for the biological reduction of N2 to NH3. Nitrogenase has been shown to reduce a variety of substrates in addition to N2 and protons. General properties of alternative substrates for nitrogenase are the presence of N-N, N-O, N-C, and C-C triple or double bonds. In the present work, we demonstrate that Azotobacter vinelandii nitrogenase can reduce both C-S and C-O bonds. Nitrogenase was found to reduce carbonyl sulfide (COS), to CO and H2S at a maximum rate of 37.2 +/- 2.0 nmol min-1 (mg of protein)-1 with a Km of 3.1 +/- 0.6 mM. The formation of CO from nitrogenase reduction of COS was monitored spectrophotometrically in real time by following the formation of carboxyhemoglobin. In this assay, the change in the visible absorption spectrum of reduced hemoglobin upon binding CO provided a sensitive way to quantify CO formation and to remove CO, which is a potent inhibitor of nitrogenase, from solution. COS reduction by nitrogenase required the molybdenum-iron protein (MoFeP), the iron protein (FeP), and MgATP. The reduction reaction was inhibited by MgADP, acetylene, and N2, while H2 was not an inhibitor of COS reduction. The pH optimum for COS reduction was 6.5. Nitrogenase was also found to reduce carbon dioxide (CO2) to CO and H2O. CO2 was reduced at a maximum rate of 0.8 +/- 0.07 nmole min-1 (mg of protein)-1 with a calculated Km for CO2 of 23.3 +/- 3.7 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of a CO: heterodisulfide oxidoreductase system from acetate-grown Methanosarcina thermophila.

During the methanogenic fermentation of acetate by Methanosarcina thermophila, the CO dehydrogenase complex cleaves acetyl coenzyme A and oxidizes the carbonyl group (or CO) to CO2, followed by electron transfer to coenzyme M (CoM)-S-S-coenzyme B (CoB) and reduction of this heterodisulfide to HS-CoM and HS-CoB (A. P. Clements, R. H. White, and J. G. Ferry, Arch. Microbiol. 159:296-300, 1993). The majority of heterodisulfide reductase activity was present in the soluble protein fraction after French pressure cell lysis. A CO:CoM-S-S-CoB oxidoreductase system from acetate-grown cells was reconstituted with purified CO dehydrogenase enzyme complex, ferredoxin, membranes, and partially purified heterodisulfide reductase. Coenzyme F420 (F420) was not required, and CO:F420 oxidoreductase activity was not detected in cell extracts. The membranes contained cytochrome b that was reduced with CO and oxidized with CoM-S-S-CoB. The results suggest that a novel CoM-S-S-CoB reducing system operates during acetate conversion to CH4 and CO2. In this system, ferredoxin transfers electrons from the CO dehydrogenase complex to membrane-bound electron carriers, including cytochrome b, that are required for electron transfer to the heterodisulfide reductase. The cytochrome b was purified from solubilized membrane proteins in a complex with six other polypeptides. The cytochrome was not reduced when the complex was incubated with H2 or CO, and H2 uptake hydrogenase activity was not detected; however, the addition of CO dehydrogenase enzyme complex and ferredoxin enabled the CO-dependent reduction of cytochrome b.

Characterization of the metal centers of the Ni/Fe-S component of the carbon-monoxide dehydrogenase enzyme complex from Methanosarcina thermophila.

Methanosarcina thermophila contains a multienzyme complex called the carbon-monoxide dehydrogenase complex, which has been resolved into a nickel/iron-sulfur and a corrinoid/iron-sulfur component. This complex plays a central role in acetoclastic methanogenesis. The Ni/Fe-S component catalyzes CO oxidation and has been proposed to be involved in cleavage of acetyl-CoA into its methyl, carbonyl, and CoA moieties. In the work reported here, three metal centers in the Ni/Fe-S component were characterized by electron paramagnetic resonance (EPR) spectroscopy and spectroelectrochemistry and pre-steady state kinetics. Center A contains nickel and iron and forms an EPR active adduct with CO, which is called the NiFeC species. The EPR spectrum of the NiFeC species has g values of 2.059, 2.051, and 2.029 and is observable at temperatures as high as 150 K. This signal had previously been observed only in the carbon-monoxide dehydrogenase complex of M. thermophila and the acetyl-CoA synthase from acetate-producing bacteria. Incubation of the CO-reduced Ni/Fe-S component with acetyl-CoA resulted in an increase in intensity of the NiFeC signal, which supports a role for the component in the cleavage of acetyl-CoA. Generation of the NiFeC EPR signal occurs with a rate constant of 0.4 s-1, a result that demonstrates the kinetic competence of this species in the acetyl-CoA cleavage reaction but rules it out as the site of oxidation of CO to CO2. Center B is likely to be a [4Fe-4S]2+/1+ center with g values of 2.04, 1.93, and 1.89 (gav = 1.95) and a standard reduction potential (E'0) of -444 mV. At potentials less than -500 mV, another EPR signal develops that appears to originate from another state of Center B. Center C is a fast relaxing center with g values of 2.02, 1.88, and 1.71 (gav = 1.87) and an E'0 of -154 mV.

Inhibition of an archaeal protein phosphatase activity by okadaic acid, microcystin-LR, or calyculin A.

Soluble extracts of the methanogenic archaeon, Methanosarcina thermophila TM-1, contained a divalent metal ion-stimulated protein-serine phosphatase activity. This activity was sensitive to micromolar concentrations of okadaic acid, microcystin-LR, or calyculin A, three compounds thought to be highly specific inhibitors of the type 1/2A/2B genetic superfamily of eukaryotic protein-serine/threonine phosphatases. The observation that each of these three chemically unrelated compounds inhibited this archaeal protein phosphatase activity suggests the existence of structural homology, and perhaps even common genetic ancestry, with the type 1/2A/2B superfamily of protein-serine/threonine phosphatases found in eukaryotic organisms.

Factors Limiting Aliphatic Chlorocarbon Degradation by Nitrosomonas europaea: Cometabolic Inactivation of Ammonia Monooxygenase and Substrate Specificity.

The soil nitrifying bacterium Nitrosomonas europaea is capable of degrading trichloroethylene (TCE) and other halogenated hydrocarbons. TCE cometabolism by N. europaea resulted in an irreversible loss of TCE biodegradative capacity, ammonia-oxidizing activity, and ammonia-dependent O(2) uptake by the cells. Inactivation was not observed in the presence of allylthiourea, a specific inhibitor of the enzyme ammonia monooxygenase, or under anaerobic conditions, indicating that the TCE-mediated inactivation required ammonia monooxygenase activity. When N. europaea cells were incubated with [C]TCE under conditions which allowed turnover of ammonia monooxygenase, a number of cellular proteins were covalently labeled with C. Treatment of cells with allylthiourea or acetylene prior to incubation with [C]TCE prevented incorporation of C into proteins. The ammonia-oxidizing activity of cells inactivated in the presence of TCE could be recovered through a process requiring de novo protein synthesis. In addition to TCE, a series of chlorinated methanes, ethanes, and other ethylenes were screened as substrates for ammonia monooxygenase and for their ability to inactivate the ammonia-oxidizing system of N. europaea. The chlorocarbons could be divided into three classes depending on their biodegradability and inactivating potential: (i) compounds which were not biodegradable by N. europaea and which had no toxic effect on the cells; (ii) compounds which were cooxidized by N. europaea and had little or no toxic effect on the cells; and (iii) compounds which were cooxidized and produced a turnover-dependent inactivation of ammonia oxidation by N. europaea.

Oxidation of monohalogenated ethanes and n-chlorinated alkanes by whole cells of Nitrosomonas europaea.

We have investigated the substrate specificity of ammonia monooxygenase in whole cells of the nitrifying bacterium Nitrosomonas europaea for a number of aliphatic halogenated hydrocarbons. To determine the effect of the halogen substituent and carbon chain length on substrate reactivity, we measured the rates of oxidation of the monohalogenated ethanes (fluoroethane, chloroethane, bromoethane, and iodoethane) and n-chlorinated C1 to C4 alkanes by whole cells of N. europaea. For monohalogenated ethanes, acetaldehyde was the major organic product and little or none of any of the alternate predicted products (2-halogenated alcohols) were detected. The maximum rate of haloethane oxidation increased with decreasing halogen molecular weight from iodoethane to chloroethane (19 to 221 nmol/min per mg of protein). In addition, the amount of substrate required for the highest rate of haloethane oxidation increased with decreasing halogen molecular weight. For the n-chlorinated alkanes, the rate of dechlorination, as measured by the appearance of the corresponding aldehyde product, was greatest for chloroethane and decreased dramatically for chloropropane and chlorobutane (118, 4, and 8 nmol of aldehyde formed per min per mg of protein, respectively). The concentration profiles for halocarbon oxidation by ammonia monooxygenase showed apparent substrate inhibition when ammonia was used as the reductant source. When hydrazine was used as the electron donor, no substrate inhibition was observed, suggesting that the inhibition resulted from reductant limitation.

Hydrogen inhibition of nitrogen reduction by nitrogenase in isolated soybean nodule bacteroids.

Dihydrogen, a by-product of biological nitrogen fixation, is a competitive inhibitor of N(2) reduction by nitrogenase. To evaluate the significance of H(2) inhibition in vivo, we have measured the apparent inhibition constant for H(2) inhibition of N(2) reduction in Bradyrhizobium japonicum bacteroids isolated from soybean nodules. The rate of N(2) reduction was measured as ammonia production by bacteroids incubated in a buffer containing 200 micromolar leghemoglobin and 10 millimolar succinate under 0.02 atmosphere O(2) and various concentrations of N(2) and H(2). The apparent inhibition constant for H(2) under these conditions was determined to be approximately 0.03 atmosphere. This relatively low value strengthens the proposal that H(2) inhibition of N(2) reduction may be a significant factor in lowering the efficiency of nitrogen fixation in legume nodules.

[Resorption of prostaglandin E2 following various methods of local administration for ripening of the cervix and end the induction of labor]. / Untersuchungen zur Resorption von Prostaglandin E2 nach unterschiedlicher lokaler Applikation zur Zervixreifung und zur Geburtseinleitung.

PGEM concentration was determined radioimmunologically in a non-pregnant woman in whom PGE2 was infused intravenously at increasing dosage and in women in whom labour was induced by various methods for local application of PGE2. There was excellent correlation between the amount of PGE2 infused intravenously and the levels of PGEM determined in the peripheral plasma. The following methods of local application of PGE2 were included in the study: 0.4 mg PGE2 gel placed retroamnially by means of a balloon catheter; 0.4 and 0.5 mg PGE2 gel applied endocervically; 1.5 mg PGE2 given pericervically through a portio adapter and 3 mg PGE2 placed intravaginally in form of a single vaginal tablet; also included was a control group where only vaginal examination was performed. Blood was withdrawn before, and then 30 minutes, 1, 2 and 3 hours after PGE2 administration. Mean levels of PGEM in the maternal peripheral plasma showed no change within or between the various groups, with the exception of one patient in the portio adapter group where hyperstimulation occurred. After removal of the adapter PGEM levels dropped to baseline values. It is concluded from the present study that local application of doses currently used to soften the cervix and/or induce labour at term does not give rise to PGEM concentrations in the maternal blood of the same magnitude as achieved by intravenous PGE2 administration.

[Premature membrane rupture: effect of intracervical PGE2 gel administration on plasma oxytocin, PGFM and PGEM levels in mother and child]. / Vorzeitiger Blasensprung: Einfluss von intrazervikaler PGE2-Gel-Gabe auf Oxytocin-, PGFM- und PGEM-Plasma-Konzentrationen bei Mutter und Kind.

Premature rupture (= PR) of the amnion is a serious complication even for the mature child if it occurs earlier than 24 hours before birth. To keep the interval as short as possible, the authors induce labour from week 35/0 in case of PR, provided the Bishop score is greater than 7. If the bishop score is lower, they conduct intracervical priming of the cervix with 0.4 mg PGE2 gel before induction of labour. This has proved clinically superior to intravenous procedures. In the study presented here, the authors attempted to find out whether intracervical administration of PGE2 gel would result in changes in the maternal and foetal plasma concentrations of oxytocin, PGFM, or PGEM when comparing conditions in case of ruptured amnion with those if the amnion remained intact. If the amnion is intact and the cervix immature (less than 2 cm), intracervical administration of 0.4 mg PGE2 gel produces a significant OT increase within 30 minutes. From a cervical width of 2 cm onwards, the OT levels are already primarily enhanced and will hardly change even after PGE2 gel administration. Similar conditions obtain in PR. PGFM plasma levels will rise only slightly within an hour after intracervical PGE2 gel administration, independent of whether there has been a rupture or not, or whether the cervix is dilated less than 2 cm or 2 cm and more.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma concentration of 13,14-dihydro-15-keto-PGE2 (PGEM) after various ways of cervix ripening with PGE2.

PGEM concentration was determined radioimmunologically in a non-pregnant woman, in whom PGE2 was infused intravenously at increasing rates and in women, in whom labor was induced by various methods for local application of PGE2. There was excellent correlation between the amount of PGE2 infused intravenously and the levels of PGEM determined in the peripheral plasma. The following methods of local application of PGE2 were included in the study: 0.4 mg PGE2 gel placed retroamnially by means of a balloon catheter, 0.4 and 0.5 mg PGE2 applied endocervically and 3 mg PGE2 placed intravaginally in form of a single vaginal tablet; also included was a control-group, where only vaginal examination was performed. Bloods were drawn before, 30 minutes, 1, 2 and 3 hours after PGE2 administration. Mean levels of PGEM in the maternal peripheral plasma did not change neither within nor between the various groups. It is concluded from the present study, that local application of doses currently used to soften the cervix and/or induce labor at term do not lead to the same PGEM-concentration in the maternal blood as after intravenous infusion of PGE2 in doses normally used to induce labor.