Termination of pregnancy in the second trimester - the course of different therapy regimens.

OBJECTIVES: To compare two prostaglandin analogs and two application intervals between mifepristone and the prostaglandin analog administration on the time to abortion in second trimester termination of pregnancy. Other endpoints were live birth rate and fetal lifetime after expulsion. METHODS: Retrospective data of 373 abortions performed were evaluated. Four medical induction subgroups and two feticide subgroups were considered. The definition criteria of the subgroups were the choice of administered prostaglandin analog (misoprostol vs. sulprostone) and the time interval between mifepristone and prostaglandin analog administration (48 vs. 24 h). The outcome parameters were the time to complete uterine evacuation (TCUE), the live birth rate and duration of fetal life. RESULTS: In the misoprostol subgroups, the median TCUE was 1.6 h longer in the 24-h group than in the 48-h group (p=0.950). In the sulprostone subgroups, the median TCUE was 1.9 h shorter in the 24-h group than in the 48-h group (p=0.950). The median TCUE was shorter for sulprostone than for misoprostol in all six subgroups (p<0.001). The rate of fetal live births ranged between 13.6 and 15.9% within the medical induction subgroups (p=0.969). The median fetal lifetime was slightly shorter in the sulprostone groups than in the misoprostol groups (p=0.563). CONCLUSIONS: Both application intervals and prostaglandin analogs are similarly effective. The therapy regime should be adapted to the personal preferences of the woman, the situational and clinical conditions.

Disinfection of Transvaginal Ultrasound Probes by Ultraviolet C - A clinical Evaluation of Automated and Manual Reprocessing Methods.

PURPOSE: Since pathogens can be transmitted to patients via transvaginal ultrasound probes, it is of particular importance that cleaning and disinfection are performed adequately. This study was designed to do a qualitative comparison of a low-level disinfection technique with disinfectant-impregnated wipes and an automated disinfection technique using ultraviolet C radiation in a clinical setting. MATERIALS AND METHODS: The transvaginal ultrasound probes used in two groups of 160 patients were compared in a prospective controlled study regarding the effectiveness of manual low-level disinfection (Mikrozid sensitive wipes) and automated disinfection using ultraviolet C radiation (Antigermix AS1). Microbiological samples were taken from the whole surface of the probe before and after the disinfection process. RESULTS: Before disinfection, 98.75 % (316/320) of the samples showed bacterial contamination. After automated and manual disinfection, the contamination rates were 34.2 % (54/158, automated) and 40.5 % (64/158, disinfectant wipes) (p > 0.05). Pathogens with the potential to cause healthcare-associated infections, such as Enterococcus faecalis and Klebsiella pneumoniae, were removed completely by both techniques. Manual disinfection showed a lower contamination rate after disinfection of bacteria that usually belong to the vaginal, pharyngeal and skin flora (disinfectant wipes 10.6 %, 11/104, automated 32.5 %, 38/117) (p < 0.001). CONCLUSION: For the clinical routine, automated disinfection with ultraviolet C is a promising technique for transvaginal ultrasound probes because of the simple handling and time efficiency. In our study, this method was completely effective against nosocomial pathogens. However, the study didn't show any significant difference in terms of effectiveness compared to low-level wipe disinfection.

Evaluation of Cervical Elastography Strain Pattern to Predict Preterm Birth.

PURPOSE: To evaluate cervical elastography strain pattern as a predictive marker for spontaneous preterm delivery (SPTD). MATERIALS AND METHODS: In this case-control study cervical length (CL) and elastographic data (strain ratio, elastography index, strain pattern score) were acquired from 335 pregnant women (20th - 34th week of gestation) by transvaginal ultrasound. Data of 50 preterm deliveries were compared with 285 normal controls. Strain ratio and elastography index were calculated by placing two regions of interest (ROIs) in parallel on the anterior cervical lip. The strain ratio was determined by dividing the higher strain value by the lower one. The elastography index was defined as the maximum of the strain ratio curve. Elastographic images were assigned a new established strain pattern (SP) score between 0 and 2 according to the distribution of strain induced by compression. RESULTS: Elastography index, SP score and CL differed between preterm and normal pregnancies (1.61 vs. 1.27, p < 0.001; SP score value of "2": n = 31 (62 %) vs. n = 36 (12.6 %), p < 0.001; CL 30.7 vs. 41.0 mm, p < 0.001; respectively). The elastography index and SP score were associated with a higher predictive potential than CL measurement alone (AUC 0.8059 (area under the curve); AUC 0.7716; AUC 0.7631; respectively). A combination of all parameters proved more predictive than any single parameter (AUC 0.8987; respectively). CONCLUSION: Higher elastography index and SP scores were correlated with an elevated risk of SPTD and are superior to CL measurement as a predictive marker. A combination of these parameters could be used as a "Cervical Index" for the prediction of SPTD.

Synthetic sideromycins (skepticism and optimism): selective generation of either broad or narrow spectrum Gram-negative antibiotics.

New or repurposed antibiotics are desperately needed since bacterial resistance has risen to essentially all of our current antibiotics, and few new antibiotics have been developed over the last several decades. A primary cause of drug resistance is the overuse of antibiotics that can result in alteration of microbial permeability, alteration of drug target binding sites, induction of enzymes that destroy antibiotics (i.e., ß-lactamases) and even induction of efflux mechanisms. Research efforts are described that are designed to determine if the known critical dependence of iron assimilation by microbes for growth and virulence can be exploited for the development of new approaches to antibiotic therapy. Iron recognition and active transport relies on the biosyntheses and use of microbe-selective iron chelating compounds called siderophores. Several natural siderophore-antibiotic conjugates (sideromycins) have been discovered and studied. The natural sideromycins consist of an iron binding siderophore linked to a warhead that exerts antibiotic activity once assimilated by targeted bacteria. Inspired these natural conjugates, a combination of chemical syntheses, microbiological and biochemical studies have been used to generate semi-synthetic and totally synthetic sideromycin analogs. The results demonstrate that siderophores and analogs can be used for iron transport-mediated drug delivery ("Trojan Horse" antibiotics or sideromycins) and induction of iron limitation/starvation (development of new agents to block iron assimilation). While several examples illustrate that this approach can generate microbe selective antibiotics that are active in vitro, the scope and limitations of this approach, especially related to development of resistance, siderophore based molecular recognition requirements, appropriate linker and drug choices, will be described.

Quantification of mechanical dyssynchrony in growth restricted fetuses and normal controls using speckle tracking echocardiography (STE).

PURPOSE: To evaluate longitudinal mechanical dyssynchrony in normally grown fetuses by speckle tracking echocardiography (STE) and to compare longitudinal mechanical dyssynchrony in fetal growth restriction (FGR) with normal controls. MATERIALS AND METHODS: A prospective study was performed on 30 FGR and 62 normally grown fetuses, including 30 controls matched by gestational age, using STE and a transversal four-chamber view. Data analysis was carried out with a high frame rate of about 175 frames/s. Dyssynchrony was analyzed offline with QLab 9 (Philips Medical Systems, Andover, MA, USA) as time differences between peaks in strain of both ventricles and the septum. Inter- and intraventricular and intraseptal dyssynchrony were obtained and inter- and intraobserver reliability was analyzed. RESULTS: Longitudinal mechanical dyssynchrony was feasible in all cases, with high inter- and intraobserver reliability. Levels of inter- and intraventricular dyssynchrony were higher in the FGR than in the control group. CONCLUSION: Speckle tracking echocardiography (STE) is a reliable technique for cardiac function assessment in the fetal heart. Interventricular dyssynchrony could be a potential parameter for early detection of subclinical myocardial dysfunction before other parameters demand intervention. The future clinical role of longitudinal mechanical dyssynchrony needs to be verified in larger studies and with a technique customized for prenatal echocardiography.

Fetal thymus size in pregnant women with diabetic diseases.

AIM: The aim of our study was to assess fetal thymus size in diabetic pregnancies compared with normal pregnancies. METHODS: Sonographic fetal thymus size was retrospectively assessed in 161 pregnancies with maternal diabetes and in 161 uncomplicated pregnancies matched by gestational age. The anteroposterior thymic and the intrathoracic mediastinal diameter were measured and the quotient was calculated [thymic-thoracic ratio (TT-ratio)]. In addition, we defined the quotient of the anteroposterior thymic diameter and the head circumference as thymus-head ratio (TH-ratio). The maternal diabetes cases were subdivided into three groups: (1) diet-controlled gestational diabetes, (2) insulin-dependent gestational diabetes and (3) preexisting maternal diabetes. RESULTS: TT-ratio and TH-ratio were smaller in pregnancies with maternal diabetes (P<0.001 and P<0.001, respectively). In all three maternal diabetes subgroups, the TT-ratio and the TH-ratio were lower compared with the control group (P<0.001 for each group). CONCLUSIONS: Reduced fetal thymus size seems to be associated with diabetic pregnancy. We introduce fetal thymus size as a new potential prognostic parameter for maternal diabetes.

Assessment of cervical elastography strain pattern and its association with preterm birth.

OBJECTIVE: The aim of the study was to assess the cervical strain pattern by an ultrasound elastography cervix examination and to determine its association with preterm delivery. METHODS: In this study, 30 cases resulting in preterm birth and 30 gestational age-matched controls were included. A vaginal ultrasound examination with cervical length and elastography measurement was performed. We calculated four strain ratios (SR1-SR4) of the regions of interest (ROIs) arranged in pairs in four different positions on the anterior cervical lip. The strain ratios were correlated to the outcome of spontaneous preterm delivery. The inter-observer and intra-observer variability of the strain measurement was evaluated. RESULTS: We observed an association between the value of the strain ratio that was calculated from the ROIs placed side by side in the middle of the anterior lip (SR4), and preterm delivery (P<0.001). The predictive values of cervical length and SR4 were comparable (AUC 0.7394; AUC 0.8322, respectively). The combination of cervical length and SR4 was superior in predicting preterm delivery compared to both parameters alone (AUC 0.8789). The inter-observer and intra-observer variability of data acquisition and measurement was excellent. CONCLUSIONS: Our study assesses the cervical elastography strain pattern and shows a correlation to a spontaneous preterm birth.

In†Vivo Dearomatization of the Potent Antituberculosis Agent BTZ043 via Meisenheimer Complex Formation.

Nitrobenzothiazinones are among the most potent antituberculosis agents. Herein, we disclose an unprecedented in vivo reduction process that affords Meisenheimer complexes of the clinical candidates BTZ043 and PBTZ169. The reduction is reversible, occurs in all mammalian species investigated, has a profound influence on the in vivo ADME characteristics, and has considerable implications for the design and implementation of clinical studies. The reduction was confirmed by chemical studies that enabled the complete characterization of the Meisenheimer complex and its subsequent chemistry. Combination of the in vivo and chemical studies with LC-MS characterization and assay development also provides a basis for rational lead optimization of this very promising class of antituberculosis agents.

Imaging of fetal thymus in pregnant women with rheumatic diseases.

OBJECTIVE: To determine whether certain rheumatic diseases will affect the fetal thymus diameter when compared to uncomplicated singleton pregnancies. Additionally, we created a reference chart for fetal thymus size in healthy singleton pregnancies from 19 to 37 weeks of gestation. METHODS: Sonographic fetal thymus size was retrospectively evaluated in 190 healthy pregnant women, and 84 pregnancies of mothers suffering from systemic lupus erythematosus, antiphospholipid syndrome (APS), or Sjögren's syndrome between 19 and 37 weeks of gestation. These fetuses were matched one-to-one for gestational age with control fetuses. The thymic-thoracic ratio (TT-ratio) was defined as the quotient of the anteroposterior thymic and the intrathoracic mediastinal diameter. RESULTS: Rheumatic diseases often affect pregnancy outcome, especially in case of primary APS. The TT ratio of fetuses of mothers suffering from rheumatic disease was equal to controls (P=0.807). CONCLUSIONS: Ours is the first study to assess the correlation of fetal thymus size in high-risk pregnancies with rheumatic diseases in comparison to controls. Women with rheumatic diseases deal with pregnancy complications more frequently than controls. Our data suggest that maternal rheumatic diseases do not affect the fetal thymus size.

Trihydroxamate siderophore-fluoroquinolone conjugates are selective sideromycin antibiotics that target Staphylococcus aureus.

Siderophores are multidentate iron(III) chelators used by bacteria for iron assimilation. Sideromycins, also called siderophore-antibiotic conjugates, are a unique subset of siderophores that enter bacterial cells via siderophore uptake pathways and deliver the toxic antibiotic in a "Trojan horse" fashion. Sideromycins represent a novel antibiotic delivery technology with untapped potential for developing sophisticated microbe-selective antibacterial agents that limit the emergence of bacterial resistance. The chemical synthesis of a series of mono-, bis-, and trihydroxamate sideromycins are described here along with their biological evaluation in antibacterial susceptibility assays. The linear hydroxamate siderophores used for the sideromycins in this study were derived from the ferrioxamine family and inspired by the naturally occurring salmycin sideromycins. The antibacterial agents used were a ß-lactam carbacepholosporin, Lorabid, and a fluoroquinolone, ciprofloxacin, chosen for the different locations of their biological targets, the periplasm (extracellular) and the cytoplasm (intracellular). The linear hydroxamate-based sideromycins were selectively toxic toward Gram-positive bacteria, especially Staphylococcus aureus SG511 (MIC = 1.0 µM for the trihydroxamate-fluoroquinolone sideromycin). Siderophore-sideromycin competition assays demonstrated that only the fluoroquinolone sideromycins required membrane transport to reach their cytoplasmic biological target and that a trihydroxamate siderophore backbone was required for protein-mediated active transport of the sideromycins into S. aureus cells via siderophore uptake pathways. This work represents a comprehensive study of linear hydroxamate sideromycins and teaches how to build effective hydroxamate-based sideromycins as Gram-positive selective antibiotic agents.

Syntheses and biological studies of novel spiropiperazinyl oxazolidinone antibacterial agents using a spirocyclic diene derived acylnitroso Diels-Alder reaction.

Several novel oxazolidinone antibiotics with a spiropiperazinyl substituent at the 4'-position of the phenyl ring were synthesized through nitroso Diels-Alder chemistry and the in vitro antibacterial activities were evaluated against various Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and mycobacteria (Mycobacterium vaccae, Mycobacterium tuberculosis). Analogs (8a and 12) were active against selected drug resistant microbes, like methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) and had no mammalian toxicity in a Hep-2 cellular assay (CC(50) >100 µM).

Design, synthesis, and study of a mycobactin-artemisinin conjugate that has selective and potent activity against tuberculosis and malaria.

Although the antimalarial agent artemisinin itself is not active against tuberculosis, conjugation to a mycobacterial-specific siderophore (microbial iron chelator) analogue induces significant and selective antituberculosis activity, including activity against multi- and extensively drug-resistant strains of Mycobacterium tuberculosis. The conjugate also retains potent antimalarial activity. Physicochemical and whole-cell studies indicated that ferric-to-ferrous reduction of the iron complex of the conjugate initiates the expected bactericidal Fenton-type radical chemistry on the artemisinin component. Thus, this "Trojan horse" approach demonstrates that new pathogen-selective therapeutic agents in which the iron component of the delivery vehicle also participates in triggering the antibiotic activity can be generated. The result is that one appropriate conjugate has potent and selective activity against two of the most deadly diseases in the world.

Syntheses and antibacterial activity studies of new oxazolidinones from nitroso Diels-Alder chemistry.

A series of novel oxazolidinone antibiotics having [2.2.1] and [2.2.2] bicyclic oxazine moieties at the C-5 side chain of the A-ring was synthesized by nitroso Diels-Alder reactions, from three linezolid analogs containing morpholine, piperazine and thiomorpholine, respectively, as the C-ring components. Subsequent N-O bond cleavage generated oxazolidinones with 4-amino cyclo-2-en-1-ol substituents. The in vitro antibacterial activities of these oxazolidinone analogs were evaluated.

Preparation and biological evaluation of novel leucomycin analogs derived from nitroso Diels-Alder reactions.

A series of 10,13-disubstituted 16-membered macrolides was synthesized using nitroso Diels-Alder reactions of leucomycin A7. Despite the extensive constituent functionalities in leucomycin, the hetero cycloaddition reactions proceeded in a highly regio- and stereoselective fashion. Subsequent chemical modifications of the nitroso cycloadducts, including N-O bond reduction, were also conducted. Most leucomycin derivatives retained antibiotic profiles similar to leucomycin A7, and, in contrast to leucomycin itself, several exhibited moderate antiproliferative and cytotoxic activity.

2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, an effective peptide antibiotic from the epiphyte Pantoea agglomerans 48b/90.

The epiphyte Pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the Enterobacteriaceae, as does the plant pathogen Erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. Since P. agglomerans efficiently antagonizes phytopathogenic bacteria, the P. agglomerans strain C9-1 is used as a biocontrol agent (BlightBan C9-1). Here we describe the bioassay-guided isolation of a peptide antibiotic that is highly active against the plant pathogen E. amylovora and pathovars of Pseudomonas syringae, and we elucidate its structure. Bioassay-guided fractionation using anion-exchange chromatography followed by hydrophobic interaction liquid chromatography yielded the bioactive, highly polar antibiotic. The compound was identified as 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine by using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance techniques. This peptide was found to be produced by three of the nine P. agglomerans strains analyzed. Notably, the biocontrol strain P. agglomerans C9-1 also produces 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine. Previously, 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been characterized only from Serratia plymuthica. 2-Amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been shown to inhibit the growth of the human pathogen Candida albicans efficiently, but its involvement in the defense of epiphytes against phytopathogenic bacteria has not been investigated so far.

Arousing sleeping genes: shifts in secondary metabolism of metal tolerant actinobacteria under conditions of heavy metal stress.

Numerous microbial habitats are strongly influenced by elevated levels of heavy metals. This type of habitat has developed either due to ore mining and metal processing or by pedogenesis above metal-rich base rocks. Most actinobacteria are soil-borne microbes with a remarkable capability for the synthesis of a broad variety of biologically active secondary metabolites. One major obstacle in identifying secondary metabolites, however, is the known phenomenon of sleeping gene clusters which are present, but silent under standard screening conditions. Here, we proceed to show that sleeping gene clusters can be awakened by the induction in heavy metal stress. Both, a chemical and a biological screening with extracts of supernatant and biomass of 10 strains derived from metal contaminated and non-contaminated environments was carried out to assay the influence of heavy metals on secondary metabolite patterns of metal tolerant actinobacteria. Metabolite patterns of cultures grown in complex and minimal media were compared to nickel (or cadmium) spiked parallels. Extracts of some strains grown in the presence of a metal salt displayed intense antibiosis against Escherichia coli, Mycobacterium smegmatis, Staphylococcus aureus and Candida albicans. Contrarily to the widely held opinion of metals as hindrance in secondary metabolism, metals thus can induce or enhance synthesis of possibly potent and medically relevant metabolites in metal tolerant strains. Hence, re-screening of existing strain libraries as well as identification of new strains from contaminated areas are valid strategies for the detection of new antibiotics in the future.

Is drug release necessary for antimicrobial activity of siderophore-drug conjugates? Syntheses and biological studies of the naturally occurring salmycin "Trojan Horse" antibiotics and synthetic desferridanoxamine-antibiotic conjugates.

The recent rise in drug resistance found amongst community acquired infections has sparked renewed interest in developing antimicrobial agents that target resistant organisms and limit the natural selection of immune variants. Recent discoveries have shown that iron uptake systems in bacteria and fungi are suitable targets for developing such therapeutic agents. The use of siderophore-drug conjugates as "Trojan Horse" drug delivery agents has attracted particular interest in this area. This review will discuss efforts in our research group to study the salmycin class of "Trojan Horse" antibiotics. Inspired by the natural design of the salmycins, a series of desferridanoxamine-antibiotic conjugates were synthesized and tested in microbial growth inhibition assays. The results of these studies will be related to understanding the role of drug release in siderophore-mediated drug delivery with implications for future siderophore-drug conjugate design.

Siderophores as drug delivery agents: application of the "Trojan Horse" strategy.

The outer membrane permeability barrier is an important resistance factor of bacterial pathogens. In combination with drug inactivating enzymes, target alteration and efflux, it can increase resistance dramatically. A strategy to overcome this membrane-mediated resistance is the misuse of bacterial transport systems. Most promising are those for iron transport. They are vital for virulence and survival of bacteria in the infected host, where iron depletion is a defense mechanism against invading pathogens. We synthesized biomimetic siderophores as shuttle vectors for active transport of antibiotics through the bacterial membrane. Structure activity relationship studies resulted in siderophore aminopenicillin conjugates that were highly active against Gram-negative pathogens which play a crucial role in destructive lung infections in cystic fibrosis patients and in severe nosocomial infections. The mechanism of action and the uptake of the compounds via specific iron siderophore transport routes were demonstrated. The novel conjugates were active against systemic Pseudomonas aeruginosa infections in mice with ED(50) values comparable to the quinolone ofloxacin and show low toxicity.

Utilization of microbial iron assimilation processes for the development of new antibiotics and inspiration for the design of new anticancer agents.

Pathogenic microbes rapidly develop resistance to antibiotics. To keep ahead in the "microbial war", extensive interdisciplinary research is needed. A primary cause of drug resistance is the overuse of antibiotics that can result in alteration of microbial permeability, alteration of drug target binding sites, induction of enzymes that destroy antibiotics (ie., beta-lactamase) and even induction of efflux mechanisms. A combination of chemical syntheses, microbiological and biochemical studies demonstrate that the known critical dependence of iron assimilation by microbes for growth and virulence can be exploited for the development of new approaches to antibiotic therapy. Iron recognition and active transport relies on the biosyntheses and use of microbe-selective iron-chelating compounds called siderophores. Our studies, and those of others, demonstrate that siderophores and analogs can be used for iron transport-mediated drug delivery ("Trojan Horse" antibiotics) and induction of iron limitation/starvation (Development of new agents to block iron assimilation). Recent extensions of the use of siderophores for the development of novel potent and selective anticancer agents are also described.

Antimicrobial, antiproliferative, cytotoxic, and tau inhibitory activity of rubellins and caeruleoramularin produced by the phytopathogenic fungus Ramularia collo-cygni.

Photodynamically active anthraquinone derivatives produced by the phytopathogenic fungus Ramularia collo-cygni are known to cause a barley leaf-spot disease, but data about light-dependent and independent bioactivity have been sparse to date. We therefore conducted for the first time a broad bioactivity profiling of rubellins B, C, D, and E and caeruleoramularin. Antibacterial but not antiviral activity is reported with light-dependent increase. Furthermore, when tested without illumination, compounds exerted antiproliferative and cytotoxic activity in a series of human tumor cell lines. Inhibition of tau protein assembly was observed as well.