Negative allosteric modulation of cannabinoid CB 1 receptor signaling suppresses opioid-mediated tolerance and withdrawal without blocking opioid antinociception

The direct blockade of CB 1 cannabinoid receptors produces therapeutic effects as well as adverse side-effects that limit their clinical potential. CB 1 negative allosteric modulators (NAMs) represent an indirect approach to decrease the affinity and/or efficacy of orthosteric cannabinoid ligands or endocannabinoids at CB 1 . We recently reported that GAT358, a CB 1 -NAM, blocked opioid-induced mesocorticolimbic dopamine release and reward via a CB 1 -allosteric mechanism of action. Whether a CB 1 -NAM dampens opioid-mediated therapeutic effects such as analgesia or alters other unwanted side-effects of opioids remain unknown. Here, we characterized the effects of GAT358 on nociceptive behaviors in the presence and absence of morphine. We examined the impact of GAT358 on formalin-evoked pain behavior and Fos protein expression, a marker of neuronal activation, in the lumbar dorsal horn. We also assessed the impact of GAT358 on morphine-induced slowing of colonic transit, tolerance, and withdrawal behaviors. GAT358 attenuated morphine antinociceptive tolerance without blocking acute antinociception. GAT358 also reduced morphine-induced slowing of colonic motility without impacting fecal boli production. GAT358 produced antinociception in the presence and absence of morphine in the formalin model of inflammatory nociception and reduced the number of formalin-evoked Fos protein-like immunoreactive cells in the lumbar spinal dorsal horn. Finally, GAT358 mitigated the somatic signs of naloxone-precipitated, but not spontaneous, opioid withdrawal following chronic morphine dosing in mice. Our results support the therapeutic potential of CB 1 -NAMs as novel drug candidates aimed at preserving opioid-mediated analgesia while preventing their unwanted side-effects. Our studies also uncover previously unrecognized antinociceptive properties associated with an arrestin-biased CB 1 -NAMs.

Highlights

CB 1 negative allosteric modulator (NAM) GAT358 attenuated morphine tolerance GAT358 reduced morphine-induced slowing of colonic motility but not fecal productionGAT358 was antinociceptive for formalin pain alone and when combined with morphineGAT358 reduced formalin-evoked Fos protein expression in the lumbar spinal cordGAT358 mitigated naloxone precipitated withdrawal after chronic morphine dosing.

First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV

We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.

Negative allosteric modulation of CB1 cannabinoid receptor signaling suppresses opioid-mediated reward

Blockade of cannabinoid type 1 (CB₁)-receptor signaling decreases the rewarding properties of many drugs of abuse and has been proposed as an anti-addiction strategy. However, psychiatric side-effects limit the clinical potential of orthosteric CB₁ antagonists. Negative allosteric modulators (NAMs) represent a novel and indirect approach to attenuate CB₁ signaling by decreasing affinity and/or efficacy of CB₁ ligands. We hypothesized that a CB₁-NAM would block opioid reward while avoiding the unwanted effects of orthosteric CB₁ antagonists. GAT358, a CB₁-NAM, failed to elicit cardinal signs of direct CB₁ activation or inactivation when administered by itself. GAT358 decreased catalepsy and hypothermia but not antinociception produced by the orthosteric CB₁ agonist CP55,940, suggesting that a CB₁-NAM blocked cardinal signs of CB₁ activation. Next, GAT358 was evaluated using in vivo assays of opioid-induced dopamine release and reward in male rodents. In the nucleus accumbens shell, a key component of the mesocorticolimbic reward pathway, morphine increased electrically-evoked dopamine efflux and this effect was blocked by a dose of GAT358 that lacked intrinsic effects on evoked dopamine efflux. Moreover, GAT358 blocked morphine-induced reward in a conditioned place preference (CPP) assay without producing reward or aversion alone. GAT358-induced blockade of morphine CPP was also occluded by GAT229, a CB₁ positive allosteric modulator (CB₁-PAM), and absent in CB₁-knockout mice. Finally, GAT358 also reduced oral oxycodone (but not water) consumption in a two-bottle choice paradigm. Our results support the therapeutic potential of CB₁-NAMs as novel drug candidates aimed at preventing opioid reward and treating opioid abuse while avoiding unwanted side-effects.

Inhibition of PSD95-nNOS protein-protein interactions decreases morphine reward and relapse vulnerability in rats

Glutamate signalling through the N-methyl-d-aspartate receptor (NMDAR) activates the enzyme neuronal nitric oxide synthase (nNOS) to produce the signalling molecule nitric oxide (NO). We hypothesized that disruption of the protein-protein interaction between nNOS and the scaffolding protein postsynaptic density 95 kDa (PSD95) would block NMDAR-dependent NO signalling and represent a viable therapeutic route to decrease opioid reward and relapse-like behaviour without the unwanted side effects of NMDAR antagonists. We used a conditioned place preference (CPP) paradigm to evaluate the impact of two small-molecule PSD95-nNOS inhibitors, IC87201 and ZL006, on the rewarding effects of morphine. Both IC87201 and ZL006 blocked morphine-induced CPP at doses that lacked intrinsic rewarding or aversive properties. Furthermore, in vivo fast-scan cyclic voltammetry (FSCV) was used to ascertain the impact of ZL006 on morphine-induced increases in dopamine (DA) efflux in the nucleus accumbens shell (NAc shell) evoked by electrical stimulation of the medial forebrain bundle (MFB). ZL006 attenuated morphine-induced increases in DA efflux at a dose that did not have intrinsic effects on DA transmission. We also employed multiple intravenous drug self-administration approaches to examine the impact of ZL006 on the reinforcing effects of morphine. Interestingly, ZL006 did not alter acquisition or maintenance of morphine self-administration, but reduced lever pressing in a morphine relapse test after forced abstinence. Our results provide behavioural and neurochemical support for the hypothesis that inhibition of PSD95-nNOS protein-protein interactions decreases morphine reward and relapse-like behaviour, highlighting a previously unreported application for these novel therapeutics in the treatment of opioid addiction.

Model-based online implementation of spike detection algorithms for neuroengineering applications

Traditional methods for the development of a neuroprosthesis to perform closed-loop stimulation can be complex and the necessary technical knowledge and experience often present a high barrier for adoption. This paper takes a novel Model-Based Design approach to simplifying such closed-loop system development, and thereby lowering the adoption barrier. This work implements a computational model of different spike detection algorithms in Simulink® and compares their performances by taking advantage of synthetic neural signals to evaluate suitability for the intended embedded implementation. Clinical Relevance--- Closed-loop systems have been demonstrated to be suitable for brain repair strategies. Coupling two different brain areas by means of a neuroprosthesis can potentially lead to restoration of communication by inducing activity-dependent plasticity.

A limited access oral oxycodone paradigm produces physical dependence and mesocorticolimbic region-dependent increases in DeltaFosB expression without preference

The abuse of oral formulations of prescription opioids has precipitated the current opioid epidemic. We developed an oral oxycodone consumption model consisting of a limited access (4 h) two-bottle choice drinking in the dark (TBC-DID) paradigm and quantified dependence with naloxone challenge using mice of both sexes. We also assessed neurobiological correlates of withdrawal and dependence elicited via oral oxycodone consumption using immunohistochemistry for DeltaFosB (ΔFosB), a transcription factor described as a molecular marker for drug addiction. Neither sex developed a preference for the oxycodone bottle, irrespective of oxycodone concentration, bottle position or prior water restriction. Mice that volitionally consumed oxycodone exhibited hyperlocomotion in an open field test and supraspinal but not spinally-mediated antinociception. Both sexes also developed robust, dose-dependent levels of opioid withdrawal that was precipitated by the opioid antagonist naloxone. Oral oxycodone consumption followed by naloxone challenge led to mesocorticolimbic region-dependent increases in the number of ΔFosB expressing cells. Naloxone-precipitated withdrawal jumps, but not the oxycodone bottle % preference, was positively correlated with the number of ΔFosB expressing cells specifically in the nucleus accumbens shell. Thus, limited access oral consumption of oxycodone produced physical dependence and increased ΔFosB expression despite the absence of opioid preference. Our TBC-DID paradigm allows for the study of oral opioid consumption in a simple, high-throughput manner and elucidates the underlying neurobiological substrates that accompany opioid-induced physical dependence.

The cross-hemispheric nigrostriatal pathway prevents the expression of levodopa-induced dyskinesias

Parkinson's disease (PD) is a neurodegenerative movement disorder that is routinely treated with levodopa. Unfortunately, long-term dopamine replacement therapy using levodopa leads to levodopa-induced dyskinesias (LID), a significant and disabling side-effect. Clinical findings indicate that LID typically only occurs following the progression of PD motor symptoms from the unilateral (Hoehn and Yahr (HY) Stage I) to the bilateral stage (HY Stage II). This suggests the presence of some compensatory interhemispheric mechanisms that delay the occurrence of LID. We therefore investigated the role of interhemispheric connections of the nigrostriatal pathway on LID expression in a rat model of PD. The striatum of one hemisphere of rats was first injected with a retrograde tracer to label the ipsi- and cross-hemispheric nigrostriatal pathways. Rats were then split into groups and unilaterally lesioned in the striatum or medial forebrain bundle of the tracer-injected hemisphere to induce varying levels of hemiparkinsonism. Finally, rats were treated with levodopa and tested for the expression of LID. Distinct subsets emerged from rats that underwent the same lesioning paradigm based on LID. Strikingly, non-dyskinetic rats had significant sparing of their cross-hemispheric nigrostriatal pathway projecting from the unlesioned hemisphere. In contrast, dyskinetic rats only had a small proportion of this cross-hemispheric nigrostriatal pathway survive lesioning. Crucially, both non-dyskinetic and dyskinetic rats had nearly identical levels of ipsi-hemispheric nigrostriatal pathway survival and parkinsonian motor deficits. Our data suggest that the survival of the cross-hemispheric nigrostriatal pathway plays a crucial role in preventing the expression of LID and represents a potentially novel target to halt the progression of this devastating side-effect of a common anti-PD therapeutic.

Spectacle wear and refractive errors in Dutch children

Background

Myopia is a refractive error that is increasing dramatically all over the world. Early onset is associated with a significant visual burden later in life, but little is known about refractive errors in preschool children. The aim of this study was to assess prevalence of spectacle wear, visual acuity and refractive errors in young Dutch children and to make global comparisons.

Methods

We analyzed data of three prospective population-based studies: 99,660 3- to 5-year-olds undergoing vision screening at preventive child healthcare organizations, 6,934 6-year-olds from the Generation R study, and 2,974 7-year-olds from the RAMSES study. Visual acuity was measured with Landolt-C or LEA charts, spectacle wear was assessed, and refractive errors at age 6 and 7 were measured with cycloplegic refraction. Spectacle wear was compared with international studies.

Results

The prevalence of spectacle wear was 1.5%, 2.3%, 6.6%, 8.2% and 11.8% at 36, 45, 60, 72 and 84 months, respectively, with no major sex differences. Among children with spectacle wear at 72 months (N = 583) and 84 months (N = 351) 29.8% and 34.6% had myopia respectively, of which 21.1% and 21.6% combined with astigmatism, 19.6% and 6.8% had hyperopia, 37.2% and 11.1% hyperopia and astigmatism, and 12.5% and 33.3% astigmatism only. The prevalence of spectacle wear globally varied between 1.5% to 21%.

Conclusions

Spectacle wear in these European children started early in preschool and increased to substantial figures at school age. Among children with spectacle wear, >30% were already myopic, illustrating the urgency to implement myopia prevention strategies in child health centers.

Key messages

Early onset myopia is a public health issue. Of the 6- to 7-year-olds with spectacles 30-34% were already myopic. Monitoring of refractive errors and preventive lifestyle interventions are warranted.

Constraints on Lightly Ionizing Particles from CDMSlite

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7}  cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5  MeV/c^{2} to 100  TeV/c^{2}) and cover a wide range of βγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with βγ as small as 0.1 for the first time.

Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst)  eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140  MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.

Comparison of peak wall stress and peak wall rupture index in ruptured and asymptomatic intact abdominal aortic aneurysms

BACKGROUND

Previous studies have suggested that finite element analysis (FEA) can estimate the rupture risk of an abdominal aortic aneurysm (AAA); however, the value of biomechanical estimates over measurement of AAA diameter alone remains unclear. This study aimed to compare peak wall stress (PWS) and peak wall rupture index (PWRI) in participants with ruptured and asymptomatic intact AAAs.

METHODS

The reproducibility of semiautomated methods for estimating aortic PWS and PWRI from CT images was assessed. PWS and PWRI were estimated in people with ruptured AAAs and those with asymptomatic intact AAAs matched by orthogonal diameter on a 1 : 2 basis. Spearman's correlation coefficient was used to assess the association between PWS or PWRI and AAA diameter. Independent associations between PWS or PWRI and AAA rupture were identified by means of logistic regression analyses.

RESULTS

Twenty individuals were included in the analysis of reproducibility. The main analysis included 50 patients with an intact AAA and 25 with a ruptured AAA. Median orthogonal diameter was similar in ruptured and intact AAAs (82·3 (i.q.r. 73·5-92·0) versus 81·0 (73·2-92·4) mm respectively; P = 0·906). Median PWS values were 286·8 (220·2-329·6) and 245·8 (215·2-302·3) kPa respectively (P = 0·192). There was no significant difference in PWRI between the two groups (P = 0·982). PWS and PWRI correlated positively with orthogonal diameter (both P < 0·001). Participants with high PWS, but not PWRI, were more likely to have a ruptured AAA after adjusting for potential confounders (odds ratio 5·84, 95 per cent c.i. 1·22 to 27·95; P = 0·027). This association was not maintained in all sensitivity analyses.

CONCLUSION

High aortic PWS had an inconsistent association with greater odds of aneurysm rupture in patients with a large AAA.

Cannabinoid CB2 Receptor Activation Attenuates Fentanyl-Induced Respiratory Depression

Introduction: Overdose fatalities associated with the opioid epidemic are predictably attributable to drug-induced respiratory depression. In terms of illicit opioid abuse, fentanyl is the synthetic opioid responsible for the largest number of overdose deaths. There is, therefore, an urgent need to identify safe and effective therapeutics that can attenuate fentanyl-induced respiratory depression. Identification of effective alternate analgesic strategies that lessen the respiratory depression associated with narcotics would also help improve current strategies for pain management. Our laboratory recently reported that the G protein-biased CB₂ cannabinoid receptor agonist LY2828360 suppressed chemotherapy-induced neuropathic nociception and attenuated both morphine tolerance and physical dependence in paclitaxel-treated mice. However, the impact of LY2828360 on other undesirable side effects of opioids, such as opioid-induced respiratory depression, remains unknown. Materials and Methods: We used whole-body plethysmography to assess the impact of the CB₂ cannabinoid agonist LY2828360 on fentanyl-induced respiratory depression using wild-type (WT) and CB₂ knockout (CB₂KO) mice. Results: Fentanyl reduced minute ventilation and respiratory frequency without altering tidal volume in both WT and CB₂KO mice. In WT mice, the high dose of fentanyl (0.2 mg/kg intraperitoneal [i.p.]) produced a greater suppression of respiratory parameters compared with the low dose of fentanyl (0.1 mg/kg i.p.). Coadministration of a behaviorally active dose of LY2828360 (3 mg/kg i.p.) with fentanyl (0.2 mg/kg i.p.) attenuated fentanyl-induced respiratory depression in WT mice. Notably, LY2828360 (3 mg/kg i.p.) did not attenuate fentanyl-induced respiratory depression in CB₂KO mice, consistent with mediation by CB₂ receptors. Moreover, LY2828360 (3 mg/kg i.p.) alone lacked intrinsic effects on respiratory parameters in either WT or CB₂KO mice. Conclusion: The combination of a CB₂ agonist with fentanyl may represent a safer adjunctive therapeutic strategy compared with a narcotic analgesic alone by attenuating the development of opioid-induced respiratory depression. Moreover, the CB₂ agonist, administered alone, did not alter respiration. Our findings suggest that the CB₂ cannabinoid agonist LY2828360 may provide CB₂-mediated protection against fentanyl-induced respiratory depression, a detrimental and unwanted side effect of opioid use and abuse.

The cannabinoid CB2 receptor agonist LY2828360 synergizes with morphine to suppress neuropathic nociception and attenuates morphine reward and physical dependence

The opioid crisis has underscored the urgent need to identify safe and effective therapeutic strategies to overcome opioid-induced liabilities. We recently reported that LY2828360, a slowly signaling G protein-biased cannabinoid CB₂ receptor agonist, suppresses neuropathic nociception and attenuates the development of tolerance to the opioid analgesic morphine in paclitaxel-treated mice. Whether beneficial effects of LY2828360 are dependent upon the presence of a pathological pain state are unknown and its impact on unwanted opioid-induced side-effects have never been investigated. Here, we asked whether LY2828360 would produce synergistic anti-allodynic effects with morphine in a paclitaxel model of chemotherapy-induced neuropathic pain and characterized its impact on opioid-induced reward and other unwanted side-effects associated with chronic opioid administration. Isobolographic analysis revealed that combinations of LY2828360 and morphine produced synergistic anti-allodynic effects in suppressing paclitaxel-induced mechanical allodynia. In wildtype (WT) mice, LY2828360 blocked morphine-induced reward in a conditioned place preference assay without producing reward or aversion when administered alone. The LY2828360-induced attenuation of morphine-induced reward was absent in CB₂ knockout (CB₂KO) mice. In the absence of a neuropathic pain state, LY2828360 partially attenuated naloxone-precipitated opioid withdrawal in morphine-dependent WT mice, and this withdrawal was itself markedly exacerbated in CB₂KO mice. Moreover, LY2828360 did not reliably alter morphine-induced slowing of colonic transit or attenuate tolerance to morphine antinociceptive efficacy in the hot plate test of acute nociception. Our results suggest that cannabinoid CB₂ receptor activation enhances the therapeutic properties of opioids while attenuating unwanted side-effects such as reward and dependence that occur with sustained opioid treatment.

Positive Allosteric Modulation of CB1 Cannabinoid Receptor Signaling Enhances Morphine Antinociception and Attenuates Morphine Tolerance Without Enhancing Morphine- Induced Dependence or Reward

Opioid analgesics represent a critical treatment for chronic pain in the analgesic ladder of the World Health Organization. However, their use can result in a number of unwanted side-effects including incomplete efficacy, constipation, physical dependence, and overdose liability. Cannabinoids enhance the pain-relieving effects of opioids in preclinical studies and dampen unwanted side-effects resulting from excessive opioid intake. We recently reported that a CB₁ positive allosteric modulator (PAM) exhibits antinociceptive efficacy in models of pathological pain and lacks the adverse side effects of direct CB₁ receptor activation. In the present study, we evaluated whether a CB₁ PAM would enhance morphine’s therapeutic efficacy in an animal model of chemotherapy-induced neuropathic pain and characterized its impact on unwanted side-effects associated with chronic opioid administration. In paclitaxel-treated mice, both the CB₁ PAM GAT211 and the opioid analgesic morphine reduced paclitaxel-induced behavioral hypersensitivities to mechanical and cold stimulation in a dose-dependent manner. Isobolographic analysis revealed that combinations of GAT211 and morphine resulted in anti-allodynic synergism. In paclitaxel-treated mice, a sub-threshold dose of GAT211 prevented the development of tolerance to the anti-allodynic effects of morphine over 20 days of once daily dosing. However, GAT211 did not reliably alter somatic withdrawal signs (i.e., jumps, paw tremors) in morphine-dependent neuropathic mice challenged with naloxone. In otherwise naïve mice, GAT211 also prolonged antinociceptive efficacy of morphine in the tail-flick test and reduced the overall right-ward shift in the ED₅₀ for morphine to produce antinociception in the tail-flick test, consistent with attenuation of morphine tolerance. Pretreatment with GAT211 did not alter somatic signs of μ opioid receptor dependence in mice rendered dependent upon morphine via subcutaneous implantation of a morphine pellet. Moreover, GAT211 did not reliably alter μ-opioid receptor-mediated reward as measured by conditioned place preference to morphine. Our results suggest that a CB₁ PAM may be beneficial in enhancing and prolonging the therapeutic properties of opioids while potentially sparing unwanted side-effects (e.g., tolerance) that occur with repeated opioid treatment.

[Responsible use of screens: recommendations to limit myopia in children and young people]

The excessive use of screens is a contemporary problem that can have a number of effects on health. It is of particular influence on the onset and exacerbation of myopia, and for these reasons a group of professionals decided to draw up recommendations on a more sensible use of screens. The group comprised an ophthalmologist-epidemiologist, an orthoptist, paediatric and adolescent physicians, a youth health care nurse, an orthopaedic surgeon, a movement therapist-epidemiologist, health scientists and psychologists. They recommend that on history-taking, standard questions concerning screen use and its associated problems should be asked. The parents can then be given targeted lifestyle advice for the child, i.e. after 20-30 minutes continuous screen use there should be a change of activity, and that the child should spend 2 hours a day outdoors. These recommendations will promote the health of children's eyes as well as their general development.

Acute levodopa dosing around-the-clock ameliorates REM sleep without atonia in hemiparkinsonian rats

Rapid-eye-movement (REM) sleep without atonia (RSWA), a marker of REM sleep behavior disorder (RBD), is frequently comorbid with Parkinson's disease (PD). Although rodent models are commonly used for studying PD, the neurobiological and behavioral correlates of RBD remain poorly understood. Therefore, we developed a behavior-based criteria to identify RSWA in the hemiparkinsonian rat model of PD. Video recordings of rats were analyzed, to develop a criteria consisting of behavioral signs that occurred during polysomnographically confirmed epochs of sleep-wake stages. The sleep-slouch, a postural shift of the body or head caused only by gravity, was identified as a unique behavioral sign of REM sleep onset and was altered in hemiparkinsonian rats during RSWA. There was a significant correlation between the behavior-based criteria and polysomnograms for all sleep-wake stages in control but not hemiparkinsonian rats indicating a deterioration of sleep-wake architecture in parkinsonism. We then tested the efficacy of levodopa in ameliorating RSWA using intermittent and around-the-clock (ATC) dosing regimens. ATC levodopa dosing at 4 mg/kg for 48 h caused a significant reduction of RSWA as measured by polysomnography and the behavioral-based criteria along with an amelioration of forelimb motor deficits. Our findings show that the phenomenological correlates of RSWA can be reliably characterized in the hemiparkinsonian rat model. ATC levodopa administration ameliorates RSWA in this model without deleterious consequences to the overall sleep-wake architecture and therapeutic benefits for parkinsonian motor deficits. These findings suggest that further study may allow for the application of a similar approach to treat RBD in PD patients.

POT1 germline mutations but not TERT promoter mutations are implicated in melanoma susceptibility in a large cohort of Spanish melanoma families

BACKGROUND

Germline mutations in telomere-related genes such as POT1 and TERT predispose individuals to familial melanoma.

OBJECTIVES

To evaluate the prevalence of germline mutations in POT1 and TERT in a large cohort of Spanish melanoma-prone families (at least two affected first- or second-degree relatives).

METHODS

Overall, 228 CDKN2A wild-type melanoma-prone families were included in the study. Screening of POT1 was performed in one affected person from each family and TERT was sequenced in one affected patient from 202 families (26 families were excluded owing to DNA exhaustion/degradation). TERT promoter sequencing was extended to an additional 30 families with CDKN2A mutation and 70 patients with sporadic multiple primary melanoma (MPM) with a family history of other cancers.

RESULTS

We identified four families with potentially pathogenic POT1 germline mutations: a missense variant c.233T>C (p.Ile78Thr); a nonsense variant c.1030G>T (p.Glu344*); and two other variants, c.255G>A (r.125_255del) and c.1792G>A (r.1791_1792insAGTA, p.Asp598Serfs*22), which we confirmed disrupted POT1 mRNA splicing. A TERT promoter variant of unknown significance (c.-125C>A) was detected in a patient with MPM, but no germline mutations were detected in TERT promoter in cases of familial melanoma.

CONCLUSIONS

Overall, 1·7% of our CDKN2A/CDK4-wild type Spanish melanoma-prone families carry probably damaging mutations in POT1. The frequency of TERT promoter germline mutations in families with melanoma in our population is extremely rare.

Erratum: First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector [Phys. Rev. Lett. 121, 051301 (2018)]

This corrects the article DOI: 10.1103/PhysRevLett.121.051301.

Brain-Permeant and -Impermeant Inhibitors of Fatty Acid Amide Hydrolase Synergize with the Opioid Analgesic Morphine to Suppress Chemotherapy-Induced Neuropathic Nociception Without Enhancing Effects of Morphine on Gastrointestinal Transit

Opioid-based therapies remain a mainstay for chronic pain management, but unwanted side effects limit therapeutic use. We compared efficacies of brain-permeant and -impermeant inhibitors of fatty acid amide hydrolase (FAAH) in suppressing neuropathic pain induced by the chemotherapeutic agent paclitaxel. Paclitaxel produced mechanical and cold allodynia without altering nestlet shredding or marble burying behaviors. We compared FAAH inhibitors that differ in their ability to penetrate the central nervous system for antiallodynic efficacy, pharmacological specificity, and synergism with the opioid analgesic morphine. (3'-(aminocarbonyl)[1,1'-biphenyl]- 3-yl)-cyclohexylcarbamate (URB597), a brain-permeant FAAH inhibitor, attenuated paclitaxel-induced allodynia via cannabinoid receptor 1 (CB₁) and cannabinoid receptor 2 (CB₂) mechanisms. URB937, a brain-impermeant FAAH inhibitor, suppressed paclitaxel-induced allodynia through a CB₁ mechanism only. 5-[4-(4-cyano-1-butyn-1-yl)phenyl]-1-(2,4-dichlorophenyl)-N-(1,1-dioxido-4-thiomorpholinyl)-4-methyl-1H-pyrazole-3-carboxamide (AM6545), a peripherally restricted CB₁ antagonist, fully reversed the antiallodynic efficacy of N-cyclohexyl-carbamic acid, 3'-(aminocarbonyl)-6-hydroxy[1,1'- biphenyl]-3-yl ester (URB937) but only partially reversed that of URB597. Thus, URB937 suppressed paclitaxel-induced allodynia through a mechanism that was dependent upon peripheral CB₁ receptor activation only. Antiallodynic effects of both FAAH inhibitors were reversed by N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). Antiallodynic effects of URB597, but not URB937, were reversed by 6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl](4-methoxyphenyl)methanone (AM630). Isobolographic analysis revealed synergistic interactions between morphine and either URB597 or URB937 in reducing paclitaxel-induced allodynia. A leftward shift in the dose-response curve of morphine antinociception was observed when morphine was coadministered with either URB597 or URB937, consistent with morphine sparing. However, neither URB937 nor URB597 enhanced morphine-induced deficits in colonic transit. Thus, our findings suggest that FAAH inhibition may represent a therapeutic avenue to reduce the overall amount of opioid needed for treating neuropathic pain with potential to reduce unwanted side effects that accompany opioid administration.

First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1  MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44})  cm^{2} at 46  GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12  GeV/c^{2}.

Alteration in steroid hormone and Her-2/neu receptor status following neoadjuvant chemotherapy in locally advanced breast cancer: Experience at a tertiary care centre in India

CONTEXT

Use of neoadjuvant chemotherapy (NACT) in locally advanced breast cancer (LABC) enables tumor reduction and conservative surgery. It is proposed in some studies that there may be an alteration in the hormonal receptor (HR) status and human epidermal growth factor receptor 2 (Her-2)/neu immune-expression following NACT.

AIMS

To study the status of estrogen receptor (ER), progesterone receptor (PR), and Her-2/neu receptor before and after NACT in LABC.

MATERIALS AND METHODS

HR and Her-2/neu status were evaluated by immunohistochemistry on 100 core needle biopsy of primary tumors and surgical specimens after receiving NACT (NACT group); fifty patients without NACT served as non-NACT group, and discordance was compared between the two groups.

RESULTS

In the NACT group, discordance of 17%, 13%, and 11% was noted in ER, PR, and Her-2/neu status, while in non-NACT group, discordance seen in ER, PR, and Her-2/neu was 8%, 8%, and 4%, respectively.

CONCLUSIONS

There was a significant alteration in ER and Her-2/neu status from the core biopsy to the treated resected tumor in the study group. As these changes may impact treatment, HR and Her-2/neu expression reanalysis in final surgical specimens is recommended.

Molecular Pathophysiology of Congenital Long QT Syndrome

Ion channels represent the molecular entities that give rise to the cardiac action potential, the fundamental cellular electrical event in the heart. The concerted function of these channels leads to normal cyclical excitation and resultant contraction of cardiac muscle. Research into cardiac ion channel regulation and mutations that underlie disease pathogenesis has greatly enhanced our knowledge of the causes and clinical management of cardiac arrhythmia. Here we review the molecular determinants, pathogenesis, and pharmacology of congenital Long QT Syndrome. We examine mechanisms of dysfunction associated with three critical cardiac currents that comprise the majority of congenital Long QT Syndrome cases: 1) IKs, the slow delayed rectifier current; 2) IKr, the rapid delayed rectifier current; and 3) INa, the voltage-dependent sodium current. Less common subtypes of congenital Long QT Syndrome affect other cardiac ionic currents that contribute to the dynamic nature of cardiac electrophysiology. Through the study of mutations that cause congenital Long QT Syndrome, the scientific community has advanced understanding of ion channel structure-function relationships, physiology, and pharmacological response to clinically employed and experimental pharmacological agents. Our understanding of congenital Long QT Syndrome continues to evolve rapidly and with great benefits: genotype-driven clinical management of the disease has improved patient care as precision medicine becomes even more a reality.

Six months versus nine months anti-tuberculous therapy for female genital tuberculosis: a randomized controlled trial

OBJECTIVE

To compare six months versus nine months anti-tuberculous therapy in patients of female genital tuberculosis.

STUDY DESIGN

It was a randomized controlled trial in a tertiary referral center teaching institute on 175 women presenting with infertility and found to have female genital tuberculosis on clinical examination and investigations. Group I women (86 women) were given 9 months of intermitted anti-tuberculous therapy under directly observed treatment short course (DOTS) strategy while Group II (89 women) were given 6 months of anti-tuberculous therapy under DOTS. Patients were evaluated for primary end points (complete cure, partial response, no response) and secondary end points (recurrence rate, pregnancy rate) during treatment. All patients were followed up further for one year after completion of therapy to assess recurrence of disease and further pregnancies.

RESULTS

Baseline characteristics were similar between two randomized groups. There was no difference in the complete clinical response rate (95.3% vs 97.7%, p=0.441) between 9-months and 6-months groups. Four patients in 9-months group and two patients in 6-months group had recurrence of disease and required category II anti tuberculous therapy (p=0.441). Pregnancy rate during treatment and up to one year follow up was also similar in the two groups (23.2% vs 21.3%, p=0.762). Side effects occurred in 27(31.4%) and 29(32.6%) in 9-months and 6-months of therapy and were similar (p=0.866).

CONCLUSIONS

There was no difference in complete cure rate, recurrent rate and pregnancy rate for either 6-months or 9-months of intermittent directly observed treatment short course anti-tuberculous therapy in female genital tuberculosis.

CLINICAL TRIAL REGISTRATION

The trial was registered in clinicaltrials.gov with registration no: CTRI/2009/091/001088.

The value of routine bone marrow biopsy in patients with diffuse large B-cell lymphoma staged with PET/CT: a Danish-Canadian study

BACKGROUND

The added diagnostic and prognostic value of routine bone marrow biopsy (BMB) in patients with diffuse large B-cell lymphoma (DLBCL) undergoing positron emission tomography combined with computed tomography (PET/CT) staging is controversial.

PATIENTS AND METHODS

Patients with newly diagnosed DLBCL who underwent both staging PET/CT and BMB were retrospectively identified in British Columbia, Aalborg, and Copenhagen. Original written PET/CT and pathology reports were retrospectively reviewed to determine Ann Arbor stage and outcomes, with and without the contribution of BMB.

RESULTS

A total of 530 patients were identified: 146 (28%) had focal bone marrow (BM) lesions on PET/CT and 87 (16%) had positive BMB. Fifty-two of 146 patients (36%) with positive PET/CT had a positive BMB [39 DLBCL, 13 indolent non-Hodgkin lymphoma (iNHL)], while 35 of 384 patients (9%) with negative PET/CT had positive BMB (12 DLBCL, 23 iNHL). BMB upstaged 12/209 (6%) of stage I/II patients to stage IV, although this was the case for only 3 (1%) patients with DLBCL in the BMB. PET/CT identified BM involvement by BMB with sensitivity 60%, specificity 79%, positive predictive value 36%, and negative predictive value 91%. Concordant histological involvement of the BM by DLBCL was associated with worse overall survival and progression-free survival than discordant or no involvement in univariate and multivariate analyses.

CONCLUSIONS

In patients with DLBCL, staging PET/CT can miss BM involvement with concordant DLBCL (less common) or discordant iNHL (more common). Routine BMB does not add relevant diagnostic or prognostic value over PET/CT alone in the majority of patients with DLBCL.

Differential responses of nitrogen-fixing cyanobacteria to salinity and osmotic stresses

Two nitrogen-fixing Anabaena strains were found to be differentially tolerant to salinity and osmotic stresses. Anabaena torulosa, a brackish-water, salt-tolerant strain, was relatively osmosensitive. Anabaena sp. strain L-31, a freshwater, salt-sensitive strain, on the other hand, displayed significant osmotolerance. Salinity and osmotic stresses affected nitrogenase activity differently. Nitrogen fixation in both of the strains was severely inhibited by the ionic, but not by the osmotic, component of salinity stress. Such differential sensitivity of diazotrophy to salinity-osmotic stresses was observed irrespective of the inherent tolerance of the two strains to salt-osmotic stress. Exogenously added ammonium conferred significant protection against salinity stress but was ineffective against osmotic stress. Salinity and osmotic stresses also affected stress-induced gene expression differently. Synthesis of several proteins was repressed by salinity stress but not by equivalent or higher osmotic stress. Salinity and osmotic stresses induced many common proteins. In addition, unique salt stress- or osmotic stress-specific proteins were also induced in both strains, indicating differential regulation of protein synthesis by the two stresses. These data show that cyanobacterial sensitivity and responses to salinity and osmotic stresses are distinct, independent phenomena.

A computational model of Purkinje fibre single cell electrophysiology: implications for the long QT syndrome

Computer modelling has emerged as a particularly useful tool in understanding the physiology and pathophysiology of cardiac tissues. Models of ventricular, atrial and nodal tissue have evolved and include detailed ion channel kinetics and intercellular Ca(2+) handling. Purkinje fibre cells play a central role in the electrophysiology of the heart and in the genesis of cardiac arrhythmias. In this study, a new computational model has been constructed that incorporates the major membrane currents that have been isolated in recent experiments using Purkinje fibre cells. The model, which integrates mathematical models of human ion channels based on detailed biophysical studies of their kinetic and voltage-dependent properties, recapitulates distinct electrophysiological characteristics unique to Purkinje fibre cells compared to neighbouring ventricular myocytes. These characteristics include automaticity, hyperpolarized voltage range of the action potential plateau potential, and prolonged action potential duration. Simulations of selective ion channel blockade reproduce responses to pharmacological challenges characteristic of isolated Purkinje fibres in vitro, and importantly, the model predicts that Purkinje fibre cells are prone to severe arrhythmogenic activity in patients harbouring long QT syndrome 3 but much less so for other common forms of long QT. This new Purkinje cellular model can be a useful tool to study tissue-specific drug interactions and the effects of disease-related ion channel dysfunction on the cardiac conduction system.

Intracerebroventricular administration of corticotrophin-releasing hormone receptor antagonists produces different effects on hypothalamic pituitary adrenal responses to novel restraint depending on the stress history of the animal

Corticotrophin-releasing hormone (CRH) regulates acute stress-induced changes in neuroendocrine function and behaviour. However, little is known about CRH functions in animals that have prior experience with repeated stress. Repeatedly-stressed rats exhibit a habituated hypothalamic-pituitary-adrenal (HPA) response to a familiar, homotypic stressor but exhibit maintained or enhanced HPA responses to a novel, heterotypic stressor. We examined the effects of intracerebroventricular (i.c.v.) administration of two different nonselective CRH receptor antagonists, alpha-helical CRH(9-41) (ahCRH) or D-Phe CRH(12-41) (D-PheCRH), on HPA responses to acute restraint in rats previously exposed to repeated cold stress (i.e. facilitated responses). Antagonists were administered as single i.c.v. injections prior to restraint to provide a general index of CRH function in control versus repeatedly-stressed rats. CRH receptor blockade with either ahCRH or D-PheCRH produced different effects on HPA responses to novel restraint depending on whether the animal had been previously cold stressed or not. Interestingly, some agonist-type effects were observed but only in repeatedly-stressed rats. In summary, these results indicate that manipulations of the CRH receptor have different effects on HPA activity depending on the stress history of the animal.

Characteristics of gait of humans with incomplete spinal cord injury

Epidural spinal cord stimulation has been demonstrated to help the recovery of walking abilities of patients with incomplete spinal cord injury when combined with partial weight bearing therapy. However, no work has been done in studying the dynamics of these signals generated with and without stimulation. We show that the underlying dynamics of such signals is chaotic. We also estimate the correlation dimension of these signals and show the difference in the dynamics of gait with and without stimulation using the kinematic data of right knee and right hip. The correlation dimension thus estimated can be used to evaluate the efficiency of epidural spinal cord stimulation in patients.

Flemish experience using the Advanta V12 stent-graft for the treatment of iliac artery occlusive disease

AIM

The aim of this study was to evaluate the technical feasibility and safety of implanting a polytetrafluoroethylene (PTFE) covered balloon expandable stent to treat iliac artery stenoses and occlusions. Additionally, the primary patency and clinical and hemodynamic efficacy at 1 year were analysed.

METHODS

This nonrandomized, prospective study involved patients with claudication and iliac artery occlusive disease at 2 participating centres. Patients with suitable lesions determined by clinical examination, ankle-brachial indices (ABIs), colour-flow duplex ultrasound (CFDU), magnetic resonance angiogram (MRA) and confirmed with biplanar digital subtraction angiography (DSA) were treated with PTFE-covered stainless steel stents. Procedural and 30-day periprocedural complications were recorded prospectively. According to in-hospital standards, follow-up with clinical ischemia category determination, ABI and CFDU was performed at 1, 6 and 12 months to determine treatment efficacy and primary limb patency.

RESULTS

In total, 91 limbs were treated in 65 patients (51 male; mean age 65 years). Stent-graft deployment was successful in 91 (100%) limbs. There were no limbs with residual stenosis >30%. There were no procedural or 30-day complications. The clinical ischemia category distribution improved significantly at 1, 6 and 12 months. The mean ABI rose significantly from 0.59 before treatment to 0.98, 0.98 and 0.99 at 1, 6 and 12 months after the procedure. Primary limb patency at 1-year was 91.1%

CONCLUSIONS

Implantation of Advanta V12 PTFE-covered stent for iliac occlusive disease shows to be safe and feasible with excellent clinical results at 1 year in the investigated patient cohort.

Osteogenesis imperfecta

Osteogenesis imperfecta is an inherited disorder of the connective tissue. The extreme bone fragility seen in patients suffering from osteogenesis imperfecta pose a series of problems with regard to behavior management and rendering of quality dental treatment. Presented here a case of a four year old child suffering from osteogenesis imperfecta.

Ensembl 2006

The Ensembl () project provides a comprehensive and integrated source of annotation of large genome sequences. Over the last year the number of genomes available from the Ensembl site has increased from 4 to 19, with the addition of the mammalian genomes of Rhesus macaque and Opossum, the chordate genome of Ciona intestinalis and the import and integration of the yeast genome. The year has also seen extensive improvements to both data analysis and presentation, with the introduction of a redesigned website, the addition of RNA gene and regulatory annotation and substantial improvements to the integration of human genome variation data.

Changes in hypothalamic-pituitary-adrenal function, body temperature, body weight and food intake with repeated social stress exposure in rats

These present studies aimed to compare changes in hypothalamic-pituitary-adrenal (HPA) activity and body temperature in response to acute social defeat, to repeated social stress and to novel restraint after repeated stress, as well as to assess effects on metabolic parameters by measuring body weight gain and food and water intake. We found that social defeat produced a marked increase in both adrenocorticotrophic hormone and corticosterone compared to placement in a novel cage. Similarly, body temperature was also increased during social defeat and during 30 min of recovery from defeat. We then examined the effects of 6 days of repeated social stress and observed minimal HPA responses to repeated social stress compared to control rats. These neuroendocrine responses were contrasted by robust increases in body temperature during stress and during recovery from stress during 6 days of repeated stress. However, in response to novel restraint, repeatedly stressed rats displayed facilitated body temperature responses compared to controls, similar to our previous findings with HPA activity. Food intake was increased during the light period during which defeat took place, but later intake during the dark period was not affected. Repeated stress decreased body weight gain in the dark period but food intake was increased overall during the 6 days of repeated stress in the light period. As a result, repeated stress increased cumulative food intake during the light period in the stressed rats but these relatively small increases in food intake were unable to prevent the diminished total weight gain in repeatedly stressed rats. Overall, the results demonstrate that, although acute social defeat has similar effects on temperature and HPA activity, repeated exposure to social stress has divergent effects on HPA activity compared to body temperature and that dampened weight gain produced by repeated social stress cannot be fully explained by changes in food intake.

Clip reconstruction for a case of peripheral posterior inferior cerebellar artery aneurysm: case report

The authors report an unusual surgical treatment for an aneurysm on the left peripheral posterior inferior cerebellar artery (PICA). The computed tomographic scan showed subarachnoid haemorrhage and a haematoma in the left cerebellar region close to the fourth ventricle. The 3D CT angiography demonstrated an aneurysm on the left peripheral PICA which was confirmed on four-vessel angiography. The aneurysm was approached through a posterior suboccipital craniotomy and the PICA was reconstructed with multiple clips. The literature concerning peripheral PICA aneurysms and their treatment is reviewed and discussed.