Preparation and evaluation of soluble epoxide hydrolase inhibitors with improved physical properties and potencies for treating diabetic neuropathic pain

Soluble epoxide hydrolase (sEH), a novel therapeutic target for neuropathic pain, is a largely cytosolic enzyme that degrades epoxy-fatty acids (EpFAs), an important class of lipid signaling molecules. Many inhibitors of sEH have been reported, and to date, the 1,3-disubstituted urea has the highest affinity reported for the sEH among the central pharmacophores evaluated. An earlier somewhat water soluble sEH inhibitor taken to the clinic for blood pressure control had mediocre potency (both affinity and kinetics) and a short in vivo half-life. We undertook a study to overcome these difficulties, but the sEH inhibitors carrying a 1,3-disubstituted urea often suffer poor physical properties that hinder their formulation. In this report, we described new strategies to improve the physical properties of sEH inhibitors with a 1,3-disubstituted urea while maintaining their potency and drug-target residence time (a complementary in vitro parameter) against sEH. To our surprise, we identified two structural modifications that substantially improve the potency and physical properties of sEH inhibitors carrying a 1,3-disubstituted urea pharmacophore. Such improvements will greatly facilitate the movement of sEH inhibitors to the clinic.

Flashbulb memory recall in healthy adults - a functional magnetic resonance imaging study

The present study investigated neural activations related to flashbulb memory (FM) recall and examined whether the amygdala and hippocampus are involved in FM recall. 20 healthy adults completed a block design with an FM-condition, where the reception events for a number of potential FM events had to be recalled, and a control condition (FMC) comprising reception events lacking FM characteristics. A definition naming task was used as an implicit baseline. The individual emotional reaction to the FM events (EMO) and self-rated retrieval success were included in the SPM model as modulating parameters. The main contrast of interest were FM > FMC and activations associated with EMO. ROI-analyses on mesiotemporal regions were performed. FM > FMC yielded activations in line with the autobiographical memory network, with mostly left sided-activations. EMO was associated with a more bilateral activation pattern. ROI-analysis revealed activations for EMO in the right amygdala and HATA. FM > FMC was associated with right hippocampal activations. The present findings are compatible with previous research into autobiographical memory, but also show activations for FM recall different from ordinary, not highly emotional autobiographical memories, as EMO is associated with a more bilateral network. Moreover, the amygdala seems to be involved in FM recall.

Cytochrome P450 derived epoxidized fatty acids as a therapeutic tool against neuroinflammatory diseases

Cytochrome P450 (CYP) metabolism of arachidonic acid (ARA) produces epoxy fatty acids (EpFAs) such as epoxyeicosatrienoic acids (EETs) that are known to exert protective effects in inflammatory disorders. Endogenous EpFAs are further metabolized into corresponding diols by the soluble epoxide hydrolase (sEH). Through inhibition of sEH, many studies have demonstrated the cardioprotective and renoprotective effects of EpFAs; however, the role of sEH inhibition in modulating the pathogenesis of neuroinflammatory disorders is less well described. In this review, we discuss the current knowledge surrounding the effects of sEH inhibition and EpFA action in neuroinflammatory disorders such as Parkinson's Disease (PD), stroke, depression, epilepsy, and Alzheimer's Disease (AD), as well as the potential mechanisms that underlie the therapeutic effects of sEH inhibition.

Productivity, Machinery and Skills in a Sample of British and German Manufacturing Plants

On the basis of interviews with management and factory floor employees at 45 matched firms in Britain and West Germany, this article examines the roles of machinery and workforce skills in explaining comparative produc tivity performance. The average age of British machinery was not very different from that found in German plants, but it was less technically advanced, was subject to more frequent breakdowns and breakdowns took longer to correct. Productivity was higher in Germany in each of our matched product groups and the importance of skills at all levels was apparent.

Temperature dependence of germination and growth in Anthurium (Araceae)

By the year 2100, temperatures are predicted to increase by about 6 °C at higher latitudes and about 3 °C in the tropics. In spite of the smaller increase in the tropics, consequences may be more severe because the climatic niches of tropical species are generally assumed to be rather narrow due to a high degree of climate stability and higher niche specialisation. However, rigorous data to back up this notion are rare. We chose the megadiverse genus Anthurium (Araceae) for study. Considering that the regeneration niche of a species is crucial for overall niche breadth, we focused on the response of germination and early growth through a temperature range of 24 °C of 15 Anthurium species, and compared the thermal niche breadth (TNB) with the temperature conditions in their current range, modelled from occurrence records. Surprisingly, an increase of 3 °C would lead to a larger overlap of TNB of germination and modelled in situ temperature conditions, while the overlap of TNB of growth with in situ conditions under current and future conditions is statistically indistinguishable. We conclude that future temperatures tend to be closer to the thermal optima of most species. Whether this really leads to an increase in performance depends on other abiotic and biotic factors, most prominently potentially changing precipitation patterns.

Epoxy Fatty Acids Are Promising Targets for Treatment of Pain, Cardiovascular Disease and Other Indications Characterized by Mitochondrial Dysfunction, Endoplasmic Stress and Inflammation

Bioactive lipid mediators resulting from the metabolism of polyunsaturated fatty acids (PUFA) are controlled by many pathways that regulate the levels of these mediators and maintain homeostasis to prevent disease. PUFA metabolism is driven primarily through three pathways. Two pathways, the cyclooxygenase (COX) and lipoxygenase (LO) enzymatic pathways, form metabolites that are mostly inflammatory, while the third route of metabolism results from the oxidation by the cytochrome P450 enzymes to form hydroxylated PUFA and epoxide metabolites. These epoxygenated fatty acids (EpFA) demonstrate largely anti-inflammatory and beneficial properties, in contrast to the other metabolites formed from the degradation of PUFA. Dysregulation of these systems often leads to chronic disease. Pharmaceutical targets of disease focus on preventing the formation of inflammatory metabolites from the COX and LO pathways, while maintaining the EpFA and increasing their concentration in the body is seen as beneficial to treating and preventing disease. The soluble epoxide hydrolase (sEH) is the major route of metabolism of EpFA. Inhibiting its activity increases concentrations of beneficial EpFA, and often disease states correlate to mutations in the sEH enzyme that increase its activity and decrease the concentrations of EpFA in the body. Recent approaches to increasing EpFA include synthetic mimics that replicate biological activity of EpFA while preventing their metabolism, while other approaches focus on developing small molecule inhibitors to the sEH. Increasing EpFA concentrations in the body has demonstrated multiple beneficial effects in treating many diseases, including inflammatory and painful conditions, cardiovascular disease, neurological and disease of the central nervous system. Demonstration of efficacy in so many disease states can be explained by the fundamental mechanism that EpFA have of maintaining healthy microvasculature and preventing mitochondrial and endoplasmic reticulum stress. While there are no FDA approved methods that target the sEH or other enzymes responsible for metabolizing EpFA, current clinical efforts to test for efficacy by increasing EpFA that include inhibiting the sEH or administration of EpFA mimics that block metabolism are in progress.

Liquid Chromatographic Method to Determine Narasin in Feedingstuffs and Premixtures: Development, Validation, and Interlaboratory Study

A reversed-phase liquid chromatography (LC) method for narasin in feedingstuffs and premixtures was developed, validated, and interlaboratory studied. The extraction solvent was methanol–K2HPO4 solution (9 + 1, v/v). Narasin was detected at 600 nm after post-column derivatization with dimethylamino-benzaldehyde. Recovery was >90%. The repeatability (RSDr) in feed (20–140 mg/kg) ranged between 1.2 and 10.5%; the within-laboratory reproducibility (RSDR) ranged between 2.2 and 4.9%. The limit of determination was <20 mg/kg. Other feed additives did not interfere in the assay. The method showed ruggedness against changes in the composition of extraction solvent, eluent, and conditions for post-column reactions. In an interlaboratory study, 5 broiler feeds (4 positive, 1 blank) and 1 premixture were analyzed by 13 laboratories. The RSDr of the feedingstuffs (20–120 mg/kg) varied between 2.17 and 7.57%. The HORRAT ranged between 0.77 and 0.88, with recoveries between 82 and 104%. One laboratory detected small signals in the blank sample, calculated as 0.6 and 2.8 mg/kg. For the premixture, acceptable results for reproducibility could only be obtained after modification of the method: the RSDr was 4.42% and the HORRAT was 1.56 (12 laboratories).

Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development

Mechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatio-temporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.

Billed and Paid Amounts for Preventive Procedures in Dental Medicaid

OBJECTIVE

To examine trends and variations in billed and paid amounts for preventive dental procedures by race/ethnicity, age, and sex in Wisconsin dental Medicaid.

METHODS

We analyzed data from the 2001 to 2013 Wisconsin Medicaid claims database for preventive dental procedures for children and adults. Billed and paid amounts for preventive dental procedures were aggregated over a visit and adjusted for inflation based on the Medical Care Consumer Price Index produced by the Bureau of Labor Statistics for 2013. Quantile regression was used to examine the trends over time and the effect of patient demographics.

RESULT

At the 50th and 75th percentiles, the overall billed amounts for preventive dental procedures were $84.97 and $105.53, and the paid amounts were $35.80 and $41.66, respectively. At the 75th percentile, there was a $2.24 increase per year in the billed amount and a $26.88 overall increase from 2001 to 2013. In the paid amount, there was a $1.34 decrease per year for an overall $16.07 decrease from 2001 to 2013. Billed and paid claims for racial/ethnic minority enrollees were $1 to $3 higher per visit at the 75th percentile when compared with those of Whites. Regarding the billed:paid ratio, White, African American, and Hispanic enrollees had values of 50% to 52%, whereas American Indians had the lowest value at 47.7%. At the 75th percentile, children aged 10 to 19 y had significantly higher billed ($26.73) and paid ($9.92) amounts than did adults aged 20 to 69 y.

CONCLUSION

The billed amount increased over time, and the paid amount decreased after adjustment for inflation. In addition, there was a wide gap between billed and paid amounts over time.

KNOWLEDGE TRANSFER STATEMENT

This study highlights clear differences between paid and billed amounts in Wisconsin dental Medicaid. The financial health of dental practices is dependent on appropriate reimbursement for dental services provided; thus, information of this nature could serve as a proxy performance measure for access to preventive dental care. Findings from this study could be used by policy makers and dental Medicaid program managers to develop outcome metrics to improve access to preventive dental services.

A giant exoplanet orbiting a very-low-mass star challenges planet formation models

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.

Computer-Aided Selective Optimization of Side Activities of Talinolol

Selective optimization of side activities is a valuable source of novel lead structures in drug discovery. In this study, a computer-aided approach was used to deorphanize the pleiotropic cholesterol-lowering effects of the beta-blocker talinolol, which result from the inhibition of the enzyme soluble epoxide hydrolase (sEH). X-ray structure analysis of the sEH in complex with talinolol enables a straightforward optimization of inhibitory potency. The resulting lead structure exhibited in vivo activity in a rat model of diabetic neuropatic pain.

Pharmaceutical Effects of Inhibiting the Soluble Epoxide Hydrolase in Canine Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that causes pain and bone deterioration driven by an increase in prostaglandins (PGs) and inflammatory cytokines. Current treatments focus on inhibiting prostaglandin production, a pro-inflammatory lipid metabolite, with NSAID drugs; however, other lipid signaling targets could provide safer and more effective treatment strategies. Epoxides of polyunsaturated fatty acids (PUFAs) are anti-inflammatory lipid mediators that are rapidly metabolized by the soluble epoxide hydrolase (sEH) into corresponding vicinal diols. Interestingly, diol levels are increased in the synovial fluid of humans with OA, warranting further research on the biological role of this lipid pathway in the progression of OA. sEH inhibitors (sEHI) stabilize these biologically active, anti-inflammatory lipid epoxides, resulting in analgesia in both neuropathic, and inflammatory pain conditions. Most experimental studies testing the analgesic effects of sEH inhibitors have used experimental rodent models, which do not completely represent the complex etiology of painful diseases. Here, we tested the efficacy of sEHI in aged dogs with natural arthritis to provide a better representation of the clinical manifestations of pain. Two sEHI were administered orally, once daily for 5 days to dogs with naturally occurring arthritis to assess efficacy and pharmacokinetics. Blinded technicians recorded the behavior of the arthritic dogs based on pre-determined criteria to assess pain and function. After 5 days, EC1728 significantly reduced pain at a dose of 5 mg/kg compared to vehicle controls. Pharmacokinetic evaluation showed concentrations exceeding the enzyme potency in both plasma and synovial fluid. In vitro data showed that epoxyeicosatrienoic acid (EETs), epoxide metabolites of arachidonic acid, decreased inflammatory cytokines, IL-6 and TNF-α, and reduced cytotoxicity in canine chondrocytes challenged with IL1β to simulate an arthritic environment. These results provide the first example of altering lipid epoxides as a therapeutic target for OA potentially acting by protecting chondrocytes from inflammatory induced cytotoxicity. Considering the challenges and high variability of naturally occurring disease in aged dogs, these data provide initial proof of concept justification that inhibiting the sEH is a non-NSAID, non-opioid, disease altering strategy for treating OA, and warrants further investigation.

Excitation of Whispering Gallery Magnons in a Magnetic Vortex

We present the generation of whispering gallery magnons with unprecedented high wave vectors via nonlinear 3-magnon scattering in a μm-sized magnetic Ni_{81}Fe_{19} disc which is in the vortex state. These modes exhibit a strong localization at the perimeter of the disc and practically zero amplitude in an extended area around the vortex core. They originate from the splitting of the fundamental radial magnon modes, which can be resonantly excited in a vortex texture by an out-of-plane microwave field. We shed light on the basics of this nonlinear scattering mechanism from an experimental and theoretical point of view. Using Brillouin light scattering microscopy, we investigated the frequency and power dependence of the 3-magnon splitting. The spatially resolved mode profiles give evidence for the localization at the boundaries of the disc and allow for a direct determination of the modes wave number.

Abstract PD5-05: Pre-therapeutic PD-L1 expression and dynamics of Ki-67 and gene expression during neoadjuvant immune-checkpoint blockade and chemotherapy to predict response within the GeparNuevo trial

Background

In the GeparNuevo trial, the PD-L1 inhibitor durvalumab increased the rate of pathologic complete response (pCR; ypT0 ypN0) in triple-negative breast cancer if treatment started in a two-week window before neoadjuvant taxane/anthracycline chemotherapy (61 % pCR vs. 41%; p = 0.048; Loibl et al. ASCO 2018). Overall, pCR rates increased only numerically from 53 % to 44 % (p = 0.281). Herein, we aimed to evaluate the predictive value of PD-L1 immunohistochemistry in pre-therapeutic core biopsies. In addition, we identified dynamics in gene expression using repeated biopsies.

Patients and Methods

174 patients were randomized to receive durvalumab or placebo with neoadjuvant chemotherapy. In the window part, 117 patients received a single dose of durvalumab (or placebo) before chemotherapy. Core biopsies were taken at three times: pre-treatment (“A”; N=174), after the window part (“B”; N=88) and after 12 weeks of nab-Paclitaxel (“C”; N=33). PD-L1 immunohistochemistry in A-biopsies (Ventana SP263 Assay) was recorded as percentage of cells with membranous staining in tumor cells and lymphocytes (TILs). We defined a tumor as PD-L1 high if ≥ 25 % of either compartment was stained. Ki-67 was stained on all available A, B and C biopsies (MIB-1, Dako, 1:100) and recorded as the percentage of tumor cells with nuclear staining. We profiled all available biopsies with targeted RNASeq using the HTG EdgeSeq platform (Oncology Biomarker panel, 2560 genes). Sequencing (IonTorrent S5) was successful in 162 A-, 79 B- and 31 C-biopsies.

Results

PD-L1 expression was high in 24 % of A-biopsies and was predictive for pCR in the complete cohort (OR 2.561; 1.183-5.554; p = 0.017). PD-L1 status of the TILs, but not of the tumor cells, was predictive (OR 1.313; 1.040-1.656; P= 0.022). The effect was not specific for durvalumab treatment. Higher levels of Ki-67 were predictive for pCR in B- biopsies in all patients (OR 1.399; 1.053-1.858; P =0.021) and in the placebo arm, but not in the durvalumab arm. Ki-67 levels in C-biopsies were not predictive; neither was the change in Ki-67 between pre-treatment and later time points (B vs. A or C vs. A).

In a differential mRNA expression analysis (A vs. B), we found seven differentially expressed genes after one dose of durvalumab. We observed strong effects on gene expression after taxane treatment (A vs. C), but no significant difference according to treatment. These genes were associated with biological processes involved in therapy response. The pre-treatment levels of 12 of 69 markedly differentially expressed genes were associated with worse response to chemotherapy.

Conclusion

In A-biopsies, PD-L1 in TILs was predictive for response, and in B-biopsies, Ki-67 was predictive, but neither marker could specifically predict response to durvalumab. We observed limited effects of a single half-dose of durvalumab on global gene expression, but could identify substantial differential expression after taxane treatment. The evaluation of gene expression dynamic offers a promising approach for the identification of resistance-associated markers.

The study was financially supported by AstraZeneca and Celgene

Citation Format: Sinn BV, Loibl S, Karn T, Untch M, Kunze CA, Weber KE, Treue D, Wagner K, Hanusch CA, Klauschen F, Fasching PA, Huober J, Zahm D-M, Jackisch C, Thomalla J, Blohmer J-U, van Mackelenbergh M, Rhiem K, Felder B, von Minckwitz G, Burchardi N, Schneeweiss A, Denkert C. Pre-therapeutic PD-L1 expression and dynamics of Ki-67 and gene expression during neoadjuvant immune-checkpoint blockade and chemotherapy to predict response within the GeparNuevo trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD5-05.

Evaluation of Lightmix Mycoplasma macrolide assay for detection of macrolide-resistant Mycoplasma pneumoniae in pneumonia patients

OBJECTIVES

Rapid detection of macrolide resistance-associated mutations in Mycoplasma pneumoniae is crucial for effective antimicrobial treatment. We evaluated the Lightmix Mycoplasma macrolide assay for the detection of point mutations at nucleotide positions 2063 and 2064 in the 23S ribosomal RNA (rRNA) gene of M. pneumoniae that confer macrolide resistance.

METHODS

Samples from 3438 patients with a respiratory tract infection were analysed by M. pneumoniae real-time PCR, and 208 (6%) of them were tested positive. In this retrospective study, 163 M. pneumoniae real-time PCR-positive samples were analysed by the Lightmix assay, and results were compared to targeted 23S rRNA sequencing.

RESULTS

Macrolide-resistant M. pneumoniae were found in 15 (9%) of 163 retrospectively analysed samples. The Lightmix assay showed a sensitivity of 100% (95% confidence interval, 78.2-100) and a specificity of 100% (95% confidence interval, 97.5-100) as the detected M. pneumoniae genotype (148 wild type and 15 non-wild type) was confirmed by 23S rRNA sequencing in all samples.

CONCLUSIONS

The Lightmix assay is an easy-to-use and accurate molecular test that allows rapid determination of macrolide resistance in M. pneumoniae.