Preclinical safety assessment of JNJ-10450232 (NTM-006), a structural analog of acetaminophen, that does not cause hepatotoxicity at supratherapeutic doses

JNJ-10450232 (NTM-006) is a new molecular entity that is structurally related to acetaminophen. A comprehensive non-clinical safety program was conducted to support first-in-human and clinical efficacy studies based on preclinical data suggesting that the compound has comparable or enhanced antinociceptive and antipyretic efficacy without causing hepatotoxicity at supratherapeutic doses. No hepatic toxicity was noted in a mouse model sensitive to acetaminophen hepatotoxicity or in rats, dogs, and non-human primates in 28-day repeat dose toxicity studies at and above doses/exposures at which acetaminophen is known to cause hepatotoxicity. In the 28-day toxicity studies, all treatment-related findings were monitorable and reversible. Methemoglobinemia, which was observed in dogs and to a lesser extent in rats, is also observed with acetaminophen. This finding is considered not relevant to humans due to species differences in metabolism. Thyroid hypertrophy and hyperplasia were also observed in dogs and were shown to be a consequence of a species-specific UGT induction also demonstrated with increased thyroid hormone metabolism. Indirect bilirubin elevation was observed in rats as a result of UGT1A1 Inhibition. JNJ-10450232 (NTM-006) had no toxicologically relevant findings in safety pharmacology or genotoxicity studies. Together, these data supported progressing into safety and efficacy studies in humans.

First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector

Dark matter with Planck-scale mass (≃10^{19}  GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19}  GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18}  cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

Time for a Fully Integrated Nonclinical-Clinical Risk Assessment to Streamline QT Prolongation Liability Determinations: A Pharma Industry Perspective

Defining an appropriate and efficient assessment of drug‐induced corrected QT interval (QTc) prolongation (a surrogate marker of torsades de pointes arrhythmia) remains a concern of drug developers and regulators worldwide. In use for over 15 years, the nonclinical International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) S7B and clinical ICH E14 guidances describe three core assays (S7B: in vitro hERG current & in vivo QTc studies; E14: thorough QT study) that are used to assess the potential of drugs to cause delayed ventricular repolarization. Incorporating these assays during nonclinical or human testing of novel compounds has led to a low prevalence of QTc‐prolonging drugs in clinical trials and no new drugs having been removed from the marketplace due to unexpected QTc prolongation. Despite this success, nonclinical evaluations of delayed repolarization still minimally influence ICH E14‐based strategies for assessing clinical QTc prolongation and defining proarrhythmic risk. In particular, the value of ICH S7B‐based “double‐negative” nonclinical findings (low risk for hERG block and in vivo QTc prolongation at relevant clinical exposures) is underappreciated. These nonclinical data have additional value in assessing the risk of clinical QTc prolongation when clinical evaluations are limited by heart rate changes, low drug exposures, or high‐dose safety considerations. The time has come to meaningfully merge nonclinical and clinical data to enable a more comprehensive, but flexible, clinical risk assessment strategy for QTc monitoring discussed in updated ICH E14 Questions and Answers. Implementing a fully integrated nonclinical/clinical risk assessment for compounds with double‐negative nonclinical findings in the context of a low prevalence of clinical QTc prolongation would relieve the burden of unnecessary clinical QTc studies and streamline drug development.

Dissimilarity of the gut-lung axis and dysbiosis of the lower airways in ventilated preterm infants

BACKGROUND

Chronic lung disease of prematurity (CLD), also called bronchopulmonary dysplasia, is a major consequence of preterm birth, but the role of the microbiome in its development remains unclear. Therefore, we assessed the progression of the bacterial community in ventilated preterm infants over time in the upper and lower airways, and assessed the gut-lung axis by comparing bacterial communities in the upper and lower airways with stool findings. Finally, we assessed whether the bacterial communities were associated with lung inflammation to suggest dysbiosis.

METHODS

We serially sampled multiple anatomical sites including the upper airway (nasopharyngeal aspirates), lower airways (tracheal aspirate fluid and bronchoalveolar lavage fluid) and the gut (stool) of ventilated preterm-born infants. Bacterial DNA load was measured in all samples and sequenced using the V3-V4 region of the 16S rRNA gene.

RESULTS

From 1102 (539 nasopharyngeal aspirates, 276 tracheal aspirate fluid, 89 bronchoalveolar lavage, 198 stool) samples from 55 preterm infants, 352 (32%) amplified suitably for 16S RNA gene sequencing. Bacterial load was low at birth and quickly increased with time, but was associated with predominant operational taxonomic units (OTUs) in all sample types. There was dissimilarity in bacterial communities between the upper and lower airways and the gut, with a separate dysbiotic inflammatory process occurring in the lower airways of infants. Individual OTUs were associated with increased inflammatory markers.

CONCLUSIONS

Taken together, these findings suggest that targeted treatment of the predominant organisms, including those not routinely treated, such as Ureaplasma spp., may decrease the development of CLD in preterm-born infants.

Monitoring reperfused myocardial infarction with delayed left ventricular systolic dysfunction in rabbits by longitudinal imaging

Background

An experimental imaging platform for longitudinal monitoring and evaluation of cardiac morphology-function changes has been long desired. We sought to establish such a platform by using a rabbit model of reperfused myocardial infarction (MI) that develops chronic left ventricle systolic dysfunction (LVSD) within 7 weeks.

Methods

Fifty-five New Zeeland white (NZW) rabbits received sham-operated or 60-min left circumflex coronary artery (LCx) ligation followed by reperfusion. Cardiac magnetic resonance imaging (cMRI), transthoracic echocardiography (echo), and blood samples were collected at baseline, in acute (48 hours or 1 week) and chronic (7 weeks) stage subsequent to MI for in vivo assessment of infarct size, cardiac morphology, LV function, and myocardial enzymes. Seven weeks post MI, animals were sacrificed and heart tissues were processed for histopathological staining.

Results

The success rate of surgical operation was 87.27%. The animal mortality rates were 12.7% and 3.6% both in acute and chronic stage separately. Serum levels of the myocardial enzyme cardiac Troponin T (cTnT) were significantly increased in MI rabbits as compared with sham animals after 4 hours of operation (P<0.05). According to cardiac morphology and function changes, 4 groups could be distinguished: sham rabbits (n=12), and MI rabbits with no (MI_NO_LVSD; n=10), moderate (MI_M_LVSD; n=9) and severe (MI_S_LVSD; n=15) LVSD. No significant differences in cardiac function or wall thickening between sham and MI_NO_LVSD rabbits were observed at both stages using both cMRI and echo methods. cMRI data showed that MI_M_LVSD rabbits exhibited a reduction of ejection fraction (EF) and an increase in end-systolic volume (ESV) at the acute phase, while at the chronic stage these parameters did not change further. Moreover, in MI_S_LVSD animals, these observations were more striking at the acute stage followed by a further decline in EF and increase in ESV at the chronic stage. Lateral wall thickening determined by cMRI was significantly decreased in MI_M_LVSD versus MI_NO_LVSD animals at both stages (P<0.05). As for MI_S_LVSD versus MI_M_LVSD rabbits, the thickening of anterior, inferior and lateral walls was significantly more decreased at both stages (P<0.05). Echo confirmed the findings of cMRI. Furthermore, these in vivo outcomes including those from vivid cine cMRI could be supported by exactly matched ex vivo histomorphological evidences.

Conclusions

Our findings indicate that chronic LVSD developed over time after surgery-induced MI in rabbits can be longitudinally evaluated using non-invasive imaging techniques and confirmed by the entire-heart-slice histomorphology. This experimental LVSD platform in rabbits may interest researchers in the field of experimental cardiology and help strengthen drug development and translational research for the management of cardiovascular diseases.

Evaluation of cardiac arrhythmic risks using a rabbit model of left ventricular systolic dysfunction

Patients with heart disease have a higher risk to develop cardiac arrhythmias, either spontaneously or drug-induced. In this study, we have used a rabbit model of myocardial infarction (MI) with severe left ventricular systolic dysfunction (LVSD) to study potential drug-induced cardiac risks with N-(piperidin-2-ylmethyl)-2,5-bis(2,2,2-trifluoroethoxy)benzamide (flecainide). Upon ligation of the left circumflex arteries, male New Zealand White rabbits developed a large MI and moderate or severe LVSD 7 weeks after surgery, in comparison to SHAM-operated animals. Subsequently, animals were exposed to escalating doses of flecainide (0.25-4 mg/kg) or solvent. Electrocardiograms (ECG) were recorded before surgery, 1 and 7 weeks after surgery and continuously during the drug protocol. The ECG biomarker iCEB (index of Cardio-Electrophysiological Balance = QT/QRS ratio) was calculated. During the ECG recording at week 1 and week 7 post MI, rabbits had no spontaneous cardiac arrhythmias. When rabbits were exposed to escalating doses of flecainide, 2 out of 5 rabbits with MI and moderate LVSD versus 0 out of 5 solvent-treated rabbits developed arrhythmias, such as ventricular tachycardia/ventricular fibrillation. These were preceded by a marked decrease of iCEB just before the onset (from 4.09 to 2.42 and from 5.56 to 2.25, respectively). Furthermore, 1 out of 5 MI rabbits with moderate LVSD and 1 out of 7 MI rabbits with severe LVSD developed total atrioventricular block after flecainide infusion and died. This rabbit model of MI and severe LVSD may be useful for preclinical evaluation of drug (similar mechanism as flecainide)-induced arrhythmic risks, which might be predicted by iCEB.

Population change of Trillium govanianum (Melanthiaceae) amid altered indigenous harvesting practices in the Indian Himalayas

ETHNOBOTANICAL RELEVANCE

Trillium govanianum Wall. ex D. Don (Melanthiaceae) is valued as a traditional medicinal herb in the Himalayan region. Applications include treatment of cancer, hypertension, neurasthenia, giddiness, arthritis, dysentery, inflammation, sepsis and reproductive disorders. Its range is highly specific, and limited to cold, shaded and moist habitats at 2400-3500 m a.s.l. Rhizomes are gathered from wild populations for trade, and this has recently emerged as a significant source of income among indigenous people of the Indian Himalayan region.

AIM

To assess the impact of changing rhizome prices on T. govanianum in the Indian Himalayan region by observing the status of existing populations and assessing the typical methods used for gathering and trade of rhizomes.

MATERIAL AND METHODS

Ecological attributes were assessed in 17 sites from Tirthan Valley (Himachal Pradesh), Munsiyari and Tunghnath (Uttarakhand). Socio-economic attributes assessed through communal focus groups and interviews with 579 medicinal plants gatherers and 19 traders, using semi-structured open ended questionnaires.

RESULTS

Population decline was highest in Munsiyari, followed by Tirthan Valley and Tunghnath, indicating that the species may become locally extinct in some areas. Methods used for gathering did not consider regeneration.

CONCLUSION

Gathering of T. govanianum from wild populations is unselective and unmanaged, raising the potential threat of local extinctions. Sustainable utilization and effective conservation is needed to protect the species and maintain community incomes. A status of 'threatened' is justified for the species in the Indian Himalayan region, due to its slow life cycle, specific habitat requirement, low population density, and commercial value.

Proximity to urban fringe recreational facilities increases native biodiversity in an arid rangeland

Urban developments affect neighbouring ecosystems in multiple ways, usually decreasing native biodiversity. Arabian arid rangeland was studied to identify the primary causes of biodiversity variation. Al Marmoum is a 990km2 area on the urban edge of Dubai, designated for ecological ‘enhancement’ and outdoor recreational use. The area lacks historical biodiversity data, but is thought to be primarily influenced by Arabian camel (Camelus dromedarius Linnaeus, 1758) herbivory. Perennial floral and faunal diversity was assessed at 54 sites. Counts of reintroduced ungulates (Arabian oryx Oryx leucoryx (Pallas, 1777), Arabian gazelle Gazella gazella cora (C.H. Smith, 1827) and sand gazelle G.subgutturosa marica (Thomas, 1897)) were made at 79 separate sites. Correlations of observed biodiversity with substrate type, anthropogenic structures, and ungulate distribution were assessed. Native biodiversity was substantially higher in north-north-west locations near recreational facilities, with the most likely cause being differential browsing pressure. Camel browsing faced greater communal regulation in the north-north-west, whereas oryx and gazelles congregated at feed points in the south-south-east that were farther from human activity. Arid rangeland in this socioecological landscape exhibits greater natural biodiversity at the urban fringe. Human activity reduces ungulate density, enabling a greater diversity of perennial flora, which then attracts non-ungulate fauna. Anthropogenic features can therefore offer conservation value in landscapes where ungulate populations are artificially elevated.

PK/PD Modelling of the QT Interval: a Step Towards Defining the Translational Relationship Between In Vitro, Awake Beagle Dogs, and Humans

Inhibiting the human ether-a-go-go-related gene (hERG)-encoded potassium ion channel is positively correlated with QT-interval prolongation in vivo, which is considered a risk factor for the occurrence of Torsades de Pointes (TdP). A pharmacokinetic/pharmacodynamic model was developed for four compounds that reached the clinic, to relate drug-induced QT-interval change in awake dogs and humans and to derive a translational scaling factor a 1. Overall, dogs were more sensitive than humans to QT-interval change, an a 1 of 1.5 was found, and a 10% current inhibition in vitro produced a higher percent QT-interval change in dogs as compared to humans. The QT-interval changes in dogs were predictive for humans. In vitro and in vivo information could reliably describe the effects in humans. Robust translational knowledge is likely to reduce the need for expensive thorough QT studies; therefore, expanding this work to more compounds is recommended.

Discovery of 3-cyclopropylmethyl-7-(4-phenylpiperidin-1-yl)-8-trifluoromethyl[1,2,4]triazolo[4,3-a]pyridine (JNJ-42153605): a positive allosteric modulator of the metabotropic glutamate 2 receptor

Advanced leads from a series of 1,2,4-triazolo[4,3-a]pyridines with mGlu2 receptor PAM activity are reported. By modification of the analogous imidazo[1,2-a]pyridine series, the newly reported leads have improved potency, in vitro ADMET, and hERG as well as good in vivo PK profile. The optimization of the series focused on improving metabolic stability while controlling lipophilicity by introducing small modifications to the scaffold substituents. Analysis of this series combined with our previously reported mGlu2 receptor PAMs showed how lipophilic ligand efficiency was improved during the course of the program. Among the best compounds, example 20 (JNJ-42153605) showed a central in vivo efficacy by inhibition of REM sleep state at a dose of 3 mg/kg po in the rat sleep-wake EEG paradigm, a phenomenon shown earlier to be mGlu2 mediated. In mice, compound 20 reversed PCP-induced hyperlocomotion with an ED₅₀ of 5.4 mg/kg sc, indicative of antipsychotic activity.

Identifying modulators of hERG channel activity using the PatchXpress planar patch clamp

The authors used the PatchXpress 7000A system to measure compound activity at the hERG channel using procedures that mimicked the "gold-standard" conventional whole-cell patch clamp. A set of 70 compounds, including hERG antagonists with potencies spanning 3 orders of magnitude, were tested on hERG302-HEK cells using protocols aimed at either identifying compound activity at a single concentration or obtaining compound potency from a cumulative concentration dependence paradigm. After exposure to compounds and subsequent washout of the wells to determine reversibility of the block, blockade by a reference compound served as a quality control. Electrical parameters and voltage dependence were similar to those obtained using a conventional whole-cell patch clamp. Rank order of compound potency was also comparable to that determined by conventional methods. One exception was flunarizine, a particularly lipophilic compound. The PatchXpress accurately identified the activity of 29 moderately potent antagonists, which only weakly displace radiolabeled astemizole and are false negatives in the binding assay. Finally, no false hits were observed from a collection of relatively inactive compounds. High-quality data acquisition by PatchXpress should help accelerate secondary screening for ion channel modulators and the drug discovery process.

Evaluation of head examinations produced with a mobile CT unit

Recent years have seen the development of mobile CT units, designed for use in operating theatres, intensive care units and accident and emergency departments. One such unit is the Tomoscan M (Philips, Utrecht, The Netherlands). It operates with a maximum tube voltage of 130 kV, and a maximum tube current of only 50 mA. This study tested whether acceptable quality CT images of the brain could be produced on the mobile unit with these parameters. 44 consecutive normal head examinations performed on the mobile scanner were compared with 35 examinations from two conventional CT units. Two independent readers scored the examinations for noise and artefact. CT dose index (CTDI) values for the three CT units were obtained in free air as an estimate of patient dose. Differences in artefact score between CT units were generally small, but noise scores were worse when using the Tomoscan M with a 2 s slice time. The lowest CTDI values were obtained with the Somatom DRH (Siemens, Erlangen, Germany) unit and the highest with the SR 7000 (Philips, Utrecht, The Netherlands), with values from Tomoscan M, in all except one case, falling between these values for the protocols used in the study. The measured scattered radiation doses from the Tomoscan M are presented.

Adrenoceptors mediating relaxation to catecholamines in rat isolated jejunum

1. The characteristics of adrenoceptors mediating relaxation to catecholamines in rat isolated jejunum were investigated. 2. Catecholamines and BRL 37344 produced relaxation of the KCl-contracted strips with an order of potency of isoprenaline (1.0) > BRL 37344 (0.63) > noradrenaline (0.1) > adrenaline (0.04). 3. In the presence of both prazosin (1 microM) and propranolol (1 microM) only small dextral shifts of the concentration-response curves to agonists were observed and an order of potency of BRL 37344 (2.5) > isoprenaline (1.0) > noradrenaline (0.2) > adrenaline (0.1) was obtained. 4. In the presence of prazosin (1 microM) and propranolol (1 microM), cyanopindolol (0.1-10 microM) produced a concentration-dependent rightward shift of the concentration-response curve to adrenaline with a Schild slope not significantly different from unity and a mean pA2 value of 7.01. 5. The resistance of relaxant responses to propranolol, the relatively high potency of BRL 37344 compared to catecholamines and the competitive antagonism of relaxant responses to adrenaline by cyanopindolol suggest that beta-adrenoceptors in rat small intestine are mainly atypical in nature.

Anatomic variation of the middle cerebral artery in the Sprague-Dawley rat

BACKGROUND AND PURPOSE

The aim of this study was to record and analyze the anatomy of the middle cerebral artery in the rat in an attempt to identify a potential source of variation of quantitative infarct measurements in commonly used models of focal cerebral ischemia.

METHODS

Over a period of 22 months, as part of ongoing studies, we routinely induced focal cerebral ischemia in 263 Sprague-Dawley rats. This was achieved by permanent occlusion of a length of the right middle cerebral artery approximately 1 to 5 mm distal to the point at which it traverses the rhinal fissure combined with 60 minutes of bilateral common carotid occlusion. The branching pattern of the middle cerebral artery was recorded for each animal by drawing and photography before occlusion and at the time of death.

RESULTS

Six distinct branching patterns were observed. The majority (82.9%) of middle cerebral arteries studied conformed to the typical bifurcating vessel commonly referred to in the literature. However, the remaining 17.1% were far more variable with major, atypical branching, introducing, we believe, unnecessary and avoidable variation into quantitative measurements of ischemia in this and similar models.

CONCLUSIONS

Middle cerebral artery anatomy should be routinely recorded in models of focal cerebral ischemia in which this artery is occluded distal to the olfactory tract, thus allowing improved analysis of data.

Inpatient admissions for interventional radiology: philosophy of patient management

As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.