[Cell-based influenza vaccines: an effective vaccine option for under 60-year-olds]

The population < 60 years of age is also affected by a significant disease burden from seasonal influenza. It carries a high economic burden, mainly driven by influenza-associated productivity losses in the working population. Conventional egg-based influenza vaccines may experience reduced effectiveness due to antigen adaptation in eggs. In contrast, cell-based influenza vaccines are less likely to be affected by antigenic adaptations to the host system and showed better effectiveness in individuals 4-64 years old over several seasons compared to conventional egg-based influenza vaccines under real-world conditions. Preferential use of cell-based influenza vaccines, as opposed to conventional egg-based vaccines, could reduce the burden of influenza-related symptoms on individuals and alleviate the economic impact on the German population < 60 years of age.

In vivo characterization of the novel ebolavirus Bombali virus suggests a low pathogenic potential for humans

Ebolaviruses cause outbreaks of haemorrhagic fever in Central and West Africa. Some members of this genus such as Ebola virus (EBOV) are highly pathogenic, with case fatality rates of up to 90%, whereas others such as Reston virus (RESTV) are apathogenic for humans. Bombali virus (BOMV) is a novel ebolavirus for which complete genome sequences were recently found in free-tailed bats, although no infectious virus could be isolated. Its pathogenic potential for humans is unknown. To address this question, we first determined whether proteins encoded by the available BOMV sequence found in Chaerephon pumilus were functional in in vitro assays. The correction of an apparent sequencing error in the glycoprotein based on these data then allowed us to generate infectious BOMV using reverse genetics and characterize its infection of human cells. Furthermore, we used HLA-A2-transgenic, NOD-scid-IL-2γ receptor-knockout (NSG-A2) mice reconstituted with human haematopoiesis as a model to evaluate the pathogenicity of BOMV in vivo in a human-like immune environment. These data demonstrate that not only does BOMV show a slower growth rate than EBOV in vitro, but it also shows low pathogenicity in humanized mice, comparable to previous studies using RESTV. Taken together, these findings suggest a low pathogenic potential of BOMV for humans.

3D Enhancement Color Maps in the Characterization of Intracranial Atherosclerotic Plaques

BACKGROUND AND PURPOSE

High-resolution MR imaging allows the identification of culprit symptomatic plaques after the administration of gadolinium. Current high-resolution MR imaging methods are limited by 2D multiplanar views and manual sampling of ROIs. We analyzed a new 3D method to objectively quantify gadolinium plaque enhancement.

MATERIALS AND METHODS

Patients with stroke due to intracranial atherosclerotic disease underwent 7T high-resolution MR imaging. 3D segmentations of the plaque and its parent vessel were generated. Signal intensity probes were automatically extended from the lumen into the plaque and the vessel wall to generate 3D enhancement color maps. Plaque gadolinium (Gd) uptake was quantified from 3D color maps as gadolinium uptake = (µPlaque T1 + Gd -µPlaque T1/SDPlaque T1). Additional metrics of enhancement such as enhancement ratio, variance, and plaque-versus-parent vessel enhancement were also calculated. Conventional 2D measures of enhancement were collected for comparison.

RESULTS

Thirty-six culprit and 44 nonculprit plaques from 36 patients were analyzed. Culprit plaques had higher gadolinium uptake than nonculprit plaques (P < .001). Gadolinium uptake was the most accurate metric for identifying culprit plaques (OR, 3.9; 95% CI 2.1-8.3). Gadolinium uptake was more sensitive (86% versus 70%) and specific (71% versus 68%) in identifying culprit plaques than conventional 2D measurements. A multivariate model, including gadolinium uptake and plaque burden, identified culprit plaques with an 83% sensitivity and 86% specificity.

CONCLUSIONS

The new 3D color map method of plaque-enhancement analysis is more accurate for identifying culprit plaques than conventional 2D methods. This new method generates a new set of metrics that could potentially be used to assess disease progression.

Identification of Rosellinia species as producers of cyclodepsipeptide PF1022 A and resurrection of the genus Dematophora as inferred from polythetic taxonomy

Rosellinia (Xylariaceae) is a large, cosmopolitan genus comprising over 130 species that have been defined based mainly on the morphology of their sexual morphs. The genus comprises both lignicolous and saprotrophic species that are frequently isolated as endophytes from healthy host plants, and important plant pathogens. In order to evaluate the utility of molecular phylogeny and secondary metabolite profiling to achieve a better basis for their classification, a set of strains was selected for a multi-locus phylogeny inferred from a combination of the sequences of the internal transcribed spacer region (ITS), the large subunit (LSU) of the nuclear rDNA, beta-tubulin (TUB2) and the second largest subunit of the RNA polymerase II (RPB2). Concurrently, various strains were surveyed for production of secondary metabolites. Metabolite profiling relied on methods with high performance liquid chromatography with diode array and mass spectrometric detection (HPLC-DAD/MS) as well as preparative isolation of the major components after re-fermentation followed by structure elucidation using nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HR-MS). Two new and nine known isopimarane diterpenoids were identified during our mycochemical studies of two selected Dematophora strains and the metabolites were tested for biological activity. In addition, the nematicidal cyclodepsipeptide PF1022 A was purified and identified from a culture of Rosellinia corticium, which is the first time that this endophyte-derived drug precursor has been identified unambiguously from an ascospore-derived isolate of a Rosellinia species. While the results of this first HPLC profiling were largely inconclusive regarding the utility of secondary metabolites as genus-specific chemotaxonomic markers, the phylogeny clearly showed that species featuring a dematophora-like asexual morph were included in a well-defined clade, for which the genus Dematophora is resurrected. Dematophora now comprises all previously known important plant pathogens in the genus such as D. arcuata, D. bunodes, D. necatrix and D. pepo, while Rosellinia s. str. comprises those species that are known to have a geniculosporium-like or nodulisporium-like asexual morph, or where the asexual morph remains unknown. The extensive morphological studies of L.E. Petrini served as a basis to transfer several further species from Rosellinia to Dematophora, based on the morphology of their asexual morphs. However, most species of Rosellinia and allies still need to be recollected in fresh state, cultured, and studied for their morphology and their phylogenetic affinities before the infrageneric relationships can be clarified.

Status quo report on wastewater treatment plant, receiving water's biocoenosis and quality as basis for evaluation of large-scale ozonation process

The project DemO₃AC (demonstration of large-scale wastewater ozonation at the Aachen-Soers wastewater treatment plant, Germany) of the Eifel-Rur Waterboard contains the construction of a large-scale ozonation plant for advanced treatment of the entire 25 million m³/yr of wastewater passing through its largest wastewater treatment plant (WWTP). In dry periods, up to 70% of the receiving water consists of treated wastewater. Thus, it is expected that effects of ozonation on downstream water biocoenosis will become observable. Extensive monitoring of receiving water and the WWTP shows a severe pollution with micropollutants (already prior to WWTP inlet). (Eco-)Toxicological investigations showed increased toxicity at the inlet of the WWTP for all assays. However, endocrine-disrupting potential was also present at other sampling points at the WWTP and in the river and could not be eliminated sufficiently by the WWTP. Total cell counts at the WWTP are slightly below average. Investigations of antibiotic resistances show no increase after the WWTP outlet in the river. However, cells carrying antibiotic-resistant genes seem to be more stress resistant in general. Comparing investigations after implementation of ozonation should lead to an approximation of the correlation between micropollutants and water quality/biocoenosis and the effects that ozonation has on this matter.

How many sonograms are needed to reliably predict the absence of fetal overgrowth in gestational diabetes mellitus pregnancies?

OBJECTIVE

Serial measurements of the fetal abdominal circumference have been used to guide metabolic management of pregnancies complicated by gestational diabetes mellitus (GDM). A reduction in the number of repeat ultrasound examinations would save resources. Our purpose was to determine the number of serial abdominal circumference measurements per patient necessary to reliably predict the absence of fetal overgrowth.

RESEARCH DESIGN AND METHODS

Women who had GDM were asked to return for repeat ultrasound at 3- to 4-week intervals starting at initiation of care (mean 26.9 ± 5.7 weeks). Maternal risk factors associated with fetal overgrowth were determined.

RESULTS

A total of 4,478 ultrasound examinations were performed on 1,914 subjects (2.3 ± 1.2 per pregnancy). Of the 518 women with fetal abdominal circumference >90th percentile, it was diagnosed in 73.9% with the first ultrasound examination at entry and in 13.1% with the second ultrasound examination. Of the fetuses, 85.9 and 86.9% of the fetuses were born non-large for gestational age (LGA) when abdominal circumference was <90th percentile at 24-27 weeks and 28-32 weeks, respectively, and 88.0% were born non-LGA when both scans showed normal growth. For those women who had no risk factors for fetal overgrowth (risk factors: BMI >30 kg/m², history of macrosomia, and fasting glucose > 100 mg/dl), the accuracy of prediction of a non-LGA neonate was 90.0, 89.5, and 95.2%. The predictive ability did not increase with more than two normal scans.

CONCLUSIONS

The yield of sonographic diagnosis of a large fetus drops markedly after the finding of a fetal abdominal circumference <90th percentile on two sonograms, which excludes with high reliability the risk of a LGA newborn. The ability was enhanced in women who had no risk factors for neonatal macrosomia.

Mechanism of colicin action: early events

The kinetics and the temperature dependence of potassium loss from Escherichia coli cells treated with colicin K have been examined. At 37 C, after a single lethal hit, essentially all of the intracellular potassium is lost within the first few minutes of treatment. The initial rate of loss is linearly related to colicin concentration up to a multiplicity of 30. As the temperature is decreased over the range from 37 to 1 C, an increasing delay is seen in the initiation of potassium loss after colicin adsorption. This delay can be overcome by increasing colicin multiplicity and probably reflects an alteration of the cell membrane at these temperatures. A comparison of this effect with an apparently related effect of temperature on the action of irehdiamine A indicates that the delay may represent the inhibition of a transmission process occurring in the membrane.

Colicin-tolerant mutants of Escherichia coli: resistance of membranes to colicin E1

Colicin E1 blocks proline accumulation by membrane vesicles prepared from wild-type sensitive Escherichia coli. Two classes of mutant cells are unaffected by colicin. Vesicles from colicin-resistant strains are sensitive to colicin E1, whereas vesicles from colicin-tolerant strains are unaffected by colicin El. These results suggest that the colicin E1 receptor is on the cell membrane and that colicin-tolerant strains have altered membranes while colicin-resistant strains have altered cell walls.

Evidence for two states of F pili

The addition of phenethyl alcohol (PEA) to cultures of male strains of Escherichia coli rapidly prevents the adsorption of the male-specific bacteriophages f1 and f2 to the donor cells. The adsorption of f2 to F pili in cell-free preparations is unaffected by PEA. In a mating system, PEA alters the kinetics of gene transfer in minimal medium but not in broth. Sodium cyanide, azide, and iodoacetate also apparently inhibit f2 adsorption to cells but not to detached F pili. The phage adsorption inhibitory action of PEA is completely reversible in the presence of 100 mug of chloramphenicol per ml.

Mechanism of action of phenethyl alcohol: breakdown of the cellular permeability barrier

Phenethyl alcohol (PEA) caused Escherichia coli to take up greatly increased amounts of acriflavine, a compound to which healthy growing cells are impermeable. PEA also caused an increased rate of efflux (leakage) of cellular potassium under conditions which do not greatly alter the influx of potassium via the energy-dependent potassium pump. We therefore propose that the primary effect of PEA is a limited breakdown of the cell membrane. The inhibition of deoxyribonucleic acid synthesis and other cellular functions would then be secondary consequences of the alteration in the membrane structure.