Discovery of Axelopran (TD-1211): A Peripherally Restricted µ-Opioid Receptor Antagonist.

The effects of opioids in the central nervous system (CNS) provide significant benefit in the treatment of pain but can also lead to physical dependence and addiction, which has contributed to a growing opioid epidemic in the United States. Gastrointestinal dysfunction is an additional serious consequence of opioid use, and this can be treated with a localized drug distribution of a non-CNS penetrant, peripherally restricted opioid receptor antagonist. Herein, we describe the application of Theravance's multivalent approach to drug discovery coupled with a physicochemical property design strategy by which the N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenyl carboxamide series of µ-opioid receptor antagonists was optimized to afford the orally absorbed, non-CNS penetrant, Phase 3 ready clinical compound axelopran (TD-1211) 19i as a potential treatment for opioid-induced constipation.

Discovery of N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenol and -phenyl carboxamide series of µ-opioid receptor antagonists.

Gastrointestinal dysfunction as a consequence of the use of opioid analgesics is of significant clinical concern. First generation drugs to treat these opioid-induced side-effects were limited by their negative impact on opioid receptor agonist-induced analgesia. Second generation therapies target a localized, peripherally-restricted, non-CNS penetrant drug distribution of opioid receptor antagonists. Herein we describe the discovery of the N-substituted-endo-3-(8-aza-bicyclo[3.2.1]oct-3-yl)-phenol and -phenyl carboxamide series of µ-opioid receptor antagonists. This report highlights the discovery of the key µ-opioid receptor antagonist pharmacophore and the optimization of in vitro metabolic stability through the application of a phenol bioisostere. The compounds 27a and 31a with the most attractive in vitro profile, formed the basis for the application of Theravance Biopharma's multivalent approach to drug discovery to afford the clinical compound axelopran (TD-1211), targeted for the treatment of opioid-induced constipation.

Head-drop: A frequent feature of late-onset myasthenia gravis.

INTRODUCTION: Head-drop is often encountered in myasthenia gravis (MG) patients, but its frequency and clinical course have not been studied systematically. METHODS: In a retrospective study of a cohort of MG patients seen over a period of 11 years in a tertiary medical center, we assessed the clinical characteristics of patients who had head-drop. RESULTS: Of 146 generalized MG patients, 15 had head-drop during the course of their disease. Head-drop patients had older age of onset than those who did not have head-drop (mean age of onset 59.1 vs. 42.3 years) and were predominantly men. Head-drop was present in 23% of patients > 60 versus 6% of those < 60 years, and it improved in 9 of 11 patients with treatment directed to generalized MG. CONCLUSIONS: Head-drop is a common, treatment-responsive manifestation of late-onset MG. Muscle Nerve 56: 441-444, 2017.

The incidence of peri-ictal prone position in patients with generalized convulsive seizures.

OBJECTIVE: The objectives of this study were to determine the incidence of peri-ictal prone position in patients with generalized convulsive seizures (GCS) and to further assess the risk of sudden unexpected death in epilepsy (SUDEP) associated with the prone position. METHOD: We retrospectively reviewed the video-EEG data of 308 GCS in 193 patients who underwent long-term video-EEG monitoring in two epilepsy centers. We determined the peri-ictal (preictal, ictal, and/or postictal) body positions. RESULTS: A peri-ictal prone position was observed in 12 (6.2%) of 193 patients and 13 (4.2%) of 308 GCS. In 5 (1.6%) of 308 GCS, patients in nonprone positions at seizure onset turned into the prone position during versive seizures. In 8 (2.6%) of 308 GCS, patients were sleeping prone at seizure onset. Peri-ictal intervention with body repositioning was provided in 11 of 12 patients and 12 of the 13 GCS. Repositioning was not provided during the remaining seizure; the patient died in the prone position. In the subset of 96 GCS without ictal intervention, patients in a supine position at seizure onset remained in the supine position at seizure termination in 57 (98.3%) of 58 GCS. Patients sleeping prone at seizure onset remained in the prone position at seizure termination in 4 (80%) of 5 GCS. CONCLUSION: Our data suggest that the incidence of peri-ictal prone position in patients with GCS is low. Both prone sleeping and forced ictal version may result in postictal prone position. Although avoiding prone sleeping may reduce the SUDEP risk, influencing forced ictal version may be difficult in the absence of supervision.

A role for jasmonates in the release of dormancy by cold stratification in wheat.

Hydration at low temperatures, commonly referred to as cold stratification, is widely used for releasing dormancy and triggering germination in a wide range of species including wheat. However, the molecular mechanism that underlies its effect on germination has largely remained unknown. Our previous studies showed that methyl-jasmonate, a derivative of jasmonic acid (JA), promotes dormancy release in wheat. In this study, we found that cold-stimulated germination of dormant grains correlated with a transient increase in JA content and expression of JA biosynthesis genes in the dormant embryos after transfer to 20 (o)C. The induction of JA production was dependent on the extent of cold imbibition and precedes germination. Blocking JA biosynthesis with acetylsalicylic acid (ASA) inhibited the cold-stimulated germination in a dose-dependent manner. In addition, we have explored the relationship between JA and abscisic acid (ABA), a well-known dormancy promoter, in cold regulation of dormancy. We found an inverse relationship between JA and ABA content in dormant wheat embryos following stratification. ABA content decreased rapidly in response to stratification, and the decrease was reversed by addition of ASA. Our results indicate that the action of JA on cold-stratified grains is mediated by suppression of two key ABA biosynthesis genes, TaNCED1 and TaNCED2.

[Atypical debut of symptoms of cholangiocarcinoma]. / Atypisk symptomdebut af kolangiokarcinom.

Malignancy of the sphenoid sinus is rare and metastasis from a cholangiocarcinoma (CC) to this location is even rarer. We present a 74-year-old female with CC metastasis to the sphenoid sinus. This case demonstrates that metastases to the sphenoid sinus occur and that the tumour can have its origin far from the head and neck region. Thus, the possibility of metastasis must always be considered when discovering a tumour in the sphenoid sinus.

Discovery of TD-4306, a long-acting ß2-agonist for the treatment of asthma and COPD.

A multivalent approach focused on amine-based secondary binding groups was applied to the discovery of long-acting inhaled ß2-agonists. Addition of amine moieties to the neutral secondary binding group of an existing ß2-agonist series was found to provide improved in vivo efficacy, but also led to the formation of biologically active aldehyde metabolites which were viewed as a risk for the development of these compounds. Structural simplification of the scaffold and blocking the site of metabolism to prevent aldehyde formation afforded a potent series of dibasic ß2-agonists with improved duration of action relative to their monobasic analogs. Additional optimization led to the discovery of 29 (TD-4306), a potent and selective ß2-agonist with potential for once-daily dosing.

Multivalent design of long-acting ß(2)-adrenoceptor agonists incorporating biarylamines.

A series of potent ß2-adrenoceptor agonists incorporating a biarylamine secondary binding group was identified. The previously reported milveterol (5), identified by a multivalent approach and containing a typical ß2-agonist primary binding group linked via a phenethylamine linker to a hydrophilic secondary binding group, served as an initiation point. A more hydrophobic set of secondary binding groups was explored, prepared rapidly from a common intermediate by Buchwald-Hartwig amination. TD-5471 (25), a potent and selective full agonist of the human ß2-adrenoceptor, was identified as the most promising agent. It is potent, with slow onset in an in vitro guinea pig trachea model and shows a dose-dependent and long duration of action in an in vivo guinea pig model of bronchoprotection. TD-5471 is structurally differentiated from milveterol and its long duration of action is consistent with a correlation with hydrophobicity observed in other long-acting ß2-agonist discovery programs.

Development of an automated dual-mode supercritical fluid chromatography and reversed-phase liquid chromatography mass-directed purification system for small-molecule drug discovery.

We report the development of a dual-mode mass-directed supercritical fluid chromatography and reversed-phase liquid chromatography purification system. The addition of a third pump allows for flexible mobile phase control between the two techniques, and enables operation of either chromatography mode within minutes by activation of a set of switching valves on a single system. Software control, fluidic pathways, interface to the mass spectrometer, and fraction collection have been modified for compatibility between both separation methods. The conditioning solvent and tuning parameters for the mass spectrometer were adjusted to achieve an ideal signal trace in either mode with good linearity (r(2) > 0.970) over a range of concentrations and minimal noise for accurate peak detection and isolation. The registration success rate is 90% and overall sample recovery for either technique is 80-90%. Combining two orthogonal separation and purification modes in one single system has improved the purification throughput of complex mixtures and has been a valuable, cost-saving tool in our laboratory.

Roles for blue light, jasmonate and nitric oxide in the regulation of dormancy and germination in wheat grain (Triticum aestivum L.).

Abscisic acid (ABA) plays a central role in seed dormancy and transcriptional regulation of genes coding for ABA biosynthetic and degradation enzymes is responsible for control of ABA content. However, little is known about signalling both before and after ABA regulation, in particular, how environmental signals are perceived and transduced. We are interested in these processes in cereal grains, particularly in relation to the development of strategies for controlling pre-harvest sprouting in barley and wheat. Our previous studies have indicated possible components of dormancy control and here we present evidence that blue light, nitric oxide (NO) and jasmonate are major controlling elements in wheat grain. Using microarray and pharmacological studies, we have found that blue light inhibits germination in dormant grain and that methyl jasmonate (MJ) and NO counteract this effect by reducing dormancy. We also present evidence that NO and jasmonate play roles in dormancy control in vivo. ABA was reduced by MJ and this was accompanied by reduced levels of expression of TaNCED1 and increased expression of TaABA8'OH-1 compared with dormant grain. Similar changes were caused by after-ripening. Analysis of global gene expression showed that although jasmonate and after-ripening caused important changes in gene expression, the changes were very different. While breaking dormancy, MJ had only a small number of target genes including gene(s) encoding beta-glucosidase. Our evidence indicates that NO and MJ act interdependently in controlling reduction of ABA and thus the demise of dormancy.

Tonic phase of a generalized convulsive seizure is an independent predictor of postictal generalized EEG suppression.

PURPOSE: To determine the incidence, duration, risk factors for, and clinical correlates of postictal generalized electroencephalography (EEG) suppression (PGES), and to further delineate the significance of PGES in the pathogenesis of sudden unexpected death in epilepsy (SUDEP). METHODS: We retrospectively reviewed the video-EEG studies of 109 consecutive patients with 151 generalized convulsive seizures (GCS) during video-EEG monitoring. We determined the incidence, duration, and clinical correlates of PGES. We also investigated whether factors such as age, sex, seizure type, total seizure duration, and duration of tonic and clonic phases influenced PGES. KEY FINDINGS: PGES was observed in 64 (58.7%) of 109 patients and in 98 (64.9%) of 151 GCS. Average duration of PGES was 42.4 ± 19.1 s. Statistical analysis showed that patients with PGES had no difference in age, gender, total seizure duration, total convulsive duration, clonic phase, seizure type, and seizure termination, as compared to those without PGES. However, tonic phase was significantly prolonged in patients with PGES than in those without PGES (p = 0.00086). A 1 s increase in tonic phase duration was associated with a 0.06 increase in log odds of PGES (odds ratio = 1.1, p = 0.00055). Clinically, 95.3% patients were unresponsive or immobile during PGES, whereas only 26.7% patients without PGES were unresponsive or immobile immediately after seizure termination. SIGNIFICANCE: PGES is a common EEG pattern of GCS. Tonic phase of GCS is an independent predictor of PGES, which is well correlated with postictal unresponsiveness or immobile, and may play a significant role in the mechanism of SUDEP.

Factors associated with excessive daytime sleepiness in patients with severe obstructive sleep apnea.

PURPOSE: Although excessive daytime sleepiness (EDS) is one of the key symptoms of obstructive sleep apnea (OSA), associations between OSA and EDS have been inconsistent, even in patients with severe OSA. To that end, our goal was to investigate factors associated with EDS based on the Epworth Sleepiness Scale (ESS) score in a large clinical population with severe OSA (apnea-hypopnea index ≥30). METHODS: This cross-sectional study included 1,126 consecutive adult patients referred for their first in-laboratory polysomnogram for suspicion of OSA. All patients completed a routine questionnaire including demographics, race, co-morbidities, sleep history, ESS, short-form quality of life questionnaire-12 (SF-12), the Center for Epidemiologic Studies Depression scale, and medications used. Severe OSA was diagnosed in 498 patients. After excluding patients taking narcotics, hypnotics, benzodiazepines, antidepressants, or those with diagnosis of depression, 355 patients remained in the final analytic cohort. Patients were divided into quartiles based on the ESS and comparisons were made between the lowest quartile (ESS ≤ 6; n = 105) and highest quartile (ESS ≥ 13; n = 97). RESULTS: Compared to the ESS ≤ 6 group, patients in the ESS ≥ 13 group had a significantly higher 3 % oxygen desaturation index and a significantly lower oxygen saturation nadir during sleep (p < 0.05). Moreover, patients with severe OSA in the highest quartile of ESS had higher depressive symptomatology. CONCLUSIONS: In patients with severe OSA, intermittent hypoxemia and depressive symptoms are important contributing factors to EDS.

Temporal disorganization of circadian rhythmicity and sleep-wake regulation in mechanically ventilated patients receiving continuous intravenous sedation.

OBJECTIVES: Sleep is regulated by circadian and homeostatic processes and is highly organized temporally. Our study was designed to determine whether this organization is preserved in patients receiving mechanical ventilation (MV) and intravenous sedation. DESIGN: Observational study. SETTING: Academic medical intensive care unit. PATIENTS: Critically ill patients receiving MV and intravenous sedation. METHODS: Continuous polysomnography (PSG) was initiated an average of 2.0 (1.0, 3.0) days after ICU admission and continued ≥ 36 h or until the patient was extubated. Sleep staging and power spectral analysis were performed using standard approaches. We also calculated the electroencephalography spectral edge frequency 95% SEF95, a parameter that is normally higher during wakefulness than during sleep. Circadian rhythmicity was assessed in 16 subjects through the measurement of aMT6s in urine samples collected hourly for 24-48 hours. Light intensity at the head of the bed was measured continuously. MEASUREMENTS AND RESULTS: We analyzed 819.7 h of PSG recordings from 21 subjects. REM sleep was identified in only 2/21 subjects. Slow wave activity lacked the normal diurnal and ultradian periodicity and homeostatic decline found in healthy adults. In nearly all patients, SEF95 was consistently low without evidence of diurnal rhythmicity (median 6.3 [5.3, 7.8] Hz, n = 18). A circadian rhythm of aMT6s excretion was present in most (13/16, 81.3%) patients, but only 4 subjects had normal timing. Comparison of the SEF95 during the melatonin-based biological night and day revealed no difference between the 2 periods (P = 0.64). CONCLUSIONS: The circadian rhythms and PSG of patients receiving mechanical ventilation and intravenous sedation exhibit pronounced temporal disorganization. The finding that most subjects exhibited preserved, but phase delayed, excretion of aMT6s suggests that the circadian pacemaker of such patients may be free-running.

Binary ionic porphyrin nanosheets: electronic and light-harvesting properties regulated by crystal structure.

Crystalline solids self-assembled from anionic and cationic porphyrins provide a new class of multifunctional optoelectronic micro- and nanomaterials. A 1 : 1 combination of zinc(II) tetra(4-sulfonatophenyl)porphyrin (ZnTPPS) and tin(IV) tetra(N-methyl-4-pyridiniumyl)porphyrin (SnTNMePyP) gives porphyrin nanosheets with high aspect ratios and varying thickness. The room temperature preparation of the nanosheets has provided the first X-ray crystal structure of a cooperative binary ionic (CBI) solid. The unit cell contains one and one-half molecules of aquo-ZnTPPS(4-) (an electron donor) and three half molecules of dihydroxy-SnTNMePyP(4+) (an electron acceptor). Charge balance in the solid is reached without any non-porphyrinic ions, as previously determined for other CBI nanomaterials by non-crystallographic means. The crystal structure reveals a complicated molecular arrangement with slipped π-π stacking only occurring in isolated dimers of one of the symmetrically unique zinc porphyrins. Consistent with the crystal structure, UV-visible J-aggregate bands indicative of exciton delocalization and extended π-π stacking are not observed. XRD measurements show that the structure of the Zn/Sn nanosheets is distinct from that of Zn/Sn four-leaf clover-like CBI solids reported previously. In contrast with the Zn/Sn clovers that do exhibit J-aggregate bands and are photoconductive, the nanosheets are not photoconductive. Even so, the nanosheets act as light-harvesting structures in an artificial photosynthesis system capable of reducing water to hydrogen but not as efficiently as the Zn/Sn clovers.

A multivalent approach to the discovery of long-acting ß(2)-adrenoceptor agonists for the treatment of asthma and COPD.

A multivalent approach was applied to the design of long-acting inhaled ß(2)-adrenoceptor agonists. A series of dimeric arylethanolamines based on the short acting ß(2)-adrenoceptor agonist albuterol were prepared, varying the nature and length of the linker between the basic nitrogens. None of the C(2)-symmetric dimers demonstrated increased potency, however dimer 5j, derived from 4-phenethylamine, was found to have increased binding potency in vitro relative to the parent monomer. Optimization of this structure led to the identification of 22 (milveterol) which demonstrates high potency in vitro and long duration of action in a guinea pig model of bronchoprotection.

Grain dormancy and light quality effects on germination in the model grass Brachypodium distachyon.

• Lack of grain dormancy in cereal crops such as barley and wheat is a common problem affecting farming areas around the world, causing losses in yield and quality because of preharvest sprouting. Control of seed or grain dormancy has been investigated extensively using various approaches in different species, including Arabidopsis and cereals. However, the use of a monocot model plant such as Brachypodium distachyon presents opportunities for the discovery of new genes related to grain dormancy that are not present in modern commercial crops. • In this work we present an anatomical description of the Brachypodium caryopsis, and we describe the dormancy behaviour of six common diploid Brachypodium inbred genotypes. We also study the effect of light quality (blue, red and far-red) on germination, and analyse changes in abscisic acid levels and gene expression between a dormant and a non-dormant Brachypodium genotype. • Our results indicate that different genotypes display high natural variability in grain dormancy and that the characteristics of dormancy and germination are similar to those found in other cereals. • We propose that Brachypodium is an ideal model for studies of grain dormancy in grasses and can be used to identify new strategies for increasing grain dormancy in crop species.

Third-generation long-acting ß2-adrenoceptor agonists: medicinal chemistry strategies employed in the identification of once-daily inhaled ß2-adrenoceptor agonists.

Inhaled long-acting ß(2)-adrenoceptor agonists (LABAs) are highly effective bronchodilators in the treatment of asthma and chronic obstructive pulmonary disease. There is significant interest in the development of third-generation compounds that improve upon the marketed twice-daily LABAs salmeterol and formoterol. A principal advantage sought from the next generation is duration of action that supports once-daily dosing, although improved efficacy, faster onset, and increased therapeutic index are also frequently cited as objectives. Recent publications detailing medicinal chemistry programs directed at the discovery of third-generation LABAs illustrate a wide variety of strategies that have been successfully employed towards these goals. Some recent scientific advances in the understanding of inhaled bronchodilators are discussed and the reported medicinal chemistry strategies are reviewed in the context of these advances.

Donor-acceptor biomorphs from the ionic self-assembly of porphyrins.

Microscale four-leaf clover-shaped structures are formed by self-assembly of anionic and cationic porphyrins. Depending on the metal complexed in the porphyrin macrocycle (Zn or Sn), the porphyrin cores are either electron donors or electron acceptors. All four combinations of these two metals in cationic tetra(N-ethanol-4-pyridinium)porphyrin and anionic tetra(sulfonatophenyl)porphyrin result in related cloverlike structures with similar crystalline packing indicated by X-ray diffraction patterns. The clover morphology transforms as the ionic strength and temperature of the self-assembly reaction are increased, but the structures maintain 4-fold symmetry. The ability to alter the electronic and photophysical properties of these solids (e.g., by altering the metals in the porphyrins) and to vary cooperative interactions between the porphyrin subunits raises the possibility of producing binary solids with tunable functionality. For example, we show that the clovers derived from anionic Zn porphyrins (electron donors) and cationic Sn porphyrins (electron acceptors) are photoconductors, but when the metals are reversed in the two porphyrins, the resulting clovers are insulators.

Molecular organization in self-assembled binary porphyrin nanotubes revealed by resonance Raman spectroscopy.

Porphyrin nanotubes were formed by the ionic self-assembly of tetrakis(4-sulfonatophenyl) porphyrin diacid (H(4)TPPS(4)(2-)) and Sn(IV) tetra(4-pyridyl) porphyrin (Sn(OH(-))(X)TPyP(4+/5+) [X = OH(-) or H(2)O]) at pH 2.0. As reported previously, the tubes are hollow as revealed by transmission electron microscopy, approximately 60 nm in diameter, and can be up to several micrometres long. The absorption spectrum of the porphyrin nanotubes presents monomer-like Soret bands, as well as two additional red-shifted bands characteristic of porphyrin J-aggregates (offset face-to-face stacks). To elucidate the origin of the J-aggregate bands and the internal interactions of the porphyrins, the resonance Raman spectra have been obtained for the porphyrin nanotubes with excitations near resonance with the Soret J-aggregate band and the monomer-like bands. The resonance Raman data reveal that the Sn porphyrins are not electronically coupled to the J-aggregates within the tubes, which are formed exclusively by H(4)TPPS(4)(2-). This suggests that the internal structure of the nanotubes has H(4)TPPS(4)(2-) in aggregates that are similar to the widely studied H(4)TPPS(4)(2-) self-aggregates and that are segregated from the Sn porphyrins. Possible internal structures of the nanotubes and mechanisms for their formation are discussed.