FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment-a pharmacokinetic-pharmacodynamic study.

BACKGROUND: Treatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone. METHODS: Opiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of 'dose-limiting toxicity' (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO2, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing. DISCUSSION: Study outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen's use in alcoholism and guidelines for the management of opiate dependence. TRIAL REGISTRATION: Clinicaltrials.gov NCT05161351. Registered on 16 December 2021.

Dosimetric and microdosimetric analyses for blood exposed to reactor-derived thermal neutrons.

Thermal neutrons are found in reactor, radiotherapy, aircraft, and space environments. The purpose of this study was to characterise the dosimetry and microdosimetry of thermal neutron exposures, using three simulation codes, as a precursor to quantitative radiobiological studies using blood samples. An irradiation line was designed employing a pyrolytic graphite crystal or-alternatively-a super mirror to expose blood samples to thermal neutrons from the National Research Universal reactor to determine radiobiological parameters. The crystal was used when assessing the relative biological effectiveness for dicentric chromosome aberrations, and other biomarkers, in lymphocytes over a low absorbed dose range of 1.2-14 mGy. Higher exposures using a super mirror will allow the additional quantification of mitochondrial responses. The physical size of the thermal neutron fields and their respective wavelength distribution was determined using the McStas Monte Carlo code. Spinning the blood samples produced a spatially uniform absorbed dose as determined from Monte Carlo N-Particle version 6 simulations. The major part (71%) of the total absorbed dose to blood was determined to be from the 14N(n,p)14C reaction and the remainder from the 1H(n,γ)2H reaction. Previous radiobiological experiments at Canadian Nuclear Laboratories involving thermal neutron irradiation of blood yielded a relative biological effectiveness of 26 ± 7. Using the Particle and Heavy Ion Transport Code System, a similar value of ∼19 for the quality factor of thermal neutrons initiating the 14N(n,p)14C reaction in soft tissue was determined by microdosimetric simulations. This calculated quality factor is of similar high value to the experimentally-derived relative biological effectiveness, and indicates the potential of thermal neutrons to induce deleterious health effects in superficial organs such as cataracts of the eye lens.

Effects of naltrexone are influenced by childhood adversity during negative emotional processing in addiction recovery.

Naltrexone is an opioid receptor antagonist used in the management of alcohol dependence. Although the endogenous opioid system has been implicated in emotion regulation, the effects of mu-opioid receptor blockade on brain systems underlying negative emotional processing are not clear in addiction. Individuals meeting criteria for alcohol dependence alone (n=18, alcohol) and in combination with cocaine and/or opioid dependence (n=21, alcohol/drugs) and healthy individuals without a history of alcohol or drug dependence (n=21) were recruited. Participants were alcohol and drug abstinent before entered into this double-blind, placebo-controlled, randomized, crossover study. Functional magnetic resonance imaging was used to investigate brain response while viewing aversive and neutral images relative to baseline on 50 mg of naltrexone and placebo. We found that naltrexone modulated task-related activation in the medial prefrontal cortex and functional connectivity between the anterior cingulate cortex and the hippocampus as a function of childhood adversity (for aversive versus neutral images) in all groups. Furthermore, there was a group-by-treatment-by-condition interaction in the right amygdala, which was mainly driven by a normalization of response for aversive relative to neutral images under naltrexone in the alcohol/drugs group. We conclude that early childhood adversity is one environmental factor that influences pharmacological response to naltrexone. Pharmacotherapy with naltrexone may also have some ameliorative effects on negative emotional processing in combined alcohol and drug dependence, possibly due to alterations in endogenous opioid transmission or the kappa-opioid receptor antagonist actions of naltrexone.

Practically convenient and industrially-aligned methods for iridium-catalysed hydrogen isotope exchange processes.

The use of alternative solvents in the iridium-catalysed hydrogen isotope exchange reaction with developing phosphine/NHC Ir(I) complexes has identified reaction media which are more widely applicable and industrially acceptable than the commonly employed chlorinated solvent, dichloromethane. Deuterium incorporation into a variety of substrates has proceeded to deliver high levels of labelling (and regioselectivity) in the presence of low catalyst loadings and over short reaction times. The preparative outputs have been complemented by DFT studies to explore ligand orientation, as well as solvent and substrate binding energies within the catalyst system.

A quantitative real-time PCR assay for the detection of Ramularia collo-cygni from barley (Hordeum vulgare).

AIMS: The aim of this study was to develop a real-time quantitative PCR test to recognize and quantify the DNA levels of the increasingly important barley pathogen Ramularia collo-cygni. METHODS AND RESULTS: The method described uses specifically designed primers and a molecular beacon probe based on an internal transcribed spacer (ITS) sequence. Pathogen extracted from barley leaves could be quantified to the picogram level in both leaves showing symptoms of infection and symptomless barley leaves. CONCLUSIONS: A relationship between R. collo-cygni DNA levels and disease symptoms was established in spring barley under natural infection conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of a test of this type and makes an important contribution to studies into the life cycle of this pathogen.

Characterisation of the effects of caffeine on sleep in the rat: a potential model of sleep disruption.

Caffeine is known to disrupt sleep and its administration to human subjects has been used to model sleep disruption. We previously showed that its effects on sleep onset latency are comparable between rats and humans. This study evaluated the potential use of caffeine as a model of sleep disruption in the rat, by assessing its effects on sleep architecture and electroencephalogram (EEG) frequency spectrum, and using sleep-promoting drugs to reverse these effects. Rats were implanted with radiotelemetry devices for body temperature, EEG, electromyogram and locomotor activity. Following recovery, animals were dosed with caffeine (10 mg/kg) alone or in combination with zolpidem (10 mg/kg) or trazodone (20 mg/kg). Sleep was scored for the subsequent 12 h using automated analysis software. Caffeine dose-dependently disrupted sleep: it increased WAKE time, decreased NREM (non-REM) sleep time and NREM bout duration (but not bout number), and decreased delta activity in NREM sleep. It also dose-dependently increased locomotor activity and body temperature. When given alone, zolpidem suppressed REM whilst trazodone increased NREM sleep time at the expense of WAKE, increased NREM bout duration, increased delta activity in NREM sleep and reduced body temperature. In combination, zolpidem attenuated caffeine's effects on WAKE, whilst trazodone attenuated its effects on NREM sleep, NREM bout duration, delta activity, body temperature and locomotor activity. Caffeine administration produced many of the signs of insomnia that were improved by two of its most successful current treatments. This model may therefore be useful in the study of new drugs for the treatment of sleep disturbance.

Effects on sleep stages and microarchitecture of caffeine and its combination with zolpidem or trazodone in healthy volunteers.

Caffeine is the world's most popular stimulant and is known to disrupt sleep. Administration of caffeine can therefore be used in healthy volunteers to mimic the effects of insomnia and thus to test the hypnotic effects of medication. This study assessed the effects of caffeine on sleep architecture and electroencephalography (EEG) spectrum alone and in combination with two different sleep-promoting medications. Home polysomnography was performed in 12 healthy male volunteers in a double-blind study whereby subjects received placebo, caffeine (150 mg), caffeine plus zolpidem (10 mg) and caffeine plus trazodone (100 mg) at bedtime in a randomised crossover design. In addition to delaying sleep onset, caffeine decreased total sleep time (TST), sleep efficiency (SE) and stage 2 sleep without significantly altering wake after sleep onset or the number of awakenings. Zolpidem attenuated the caffeine-induced decrease in SE and increased spindle density in the caffeine plus zolpidem combination compared with placebo. Trazodone attenuated the decrease in SE and TST, and it also increased stage 3 sleep, decreased the number of awakenings and decreased the spindle density. No significant changes in rapid eye movement (REM) sleep were observed, neither was any significant alteration in slow wave activity nor other EEG spectral measures, although the direction of change was similar to that previously reported for caffeine and appeared to 'normalise' after trazodone. These data suggest that caffeine mimics some, but not all of the sleep disruption seen in insomnia and that its disruptive effects are differentially attenuated by the actions of sleep-promoting compounds with distinct mechanisms of action.

Dual beam fibre trap for Raman micro-spectroscopy of single cells.

Raman spectroscopy permits acquisition of molecular signatures from both cellular and sub-cellular samples. When combined with optical trapping we may interrogate an isolated cell reducing extraneous signals from the local environment. To date, experimental configurations have employed combinations of the single beam optical tweezers trap and Raman spectroscopy, using either the same beam or separate beams for Raman interrogation and trapping. A key problem in optical tweezers is the ability to hold and manoeuvre large cells. In this paper, we use a dual beam fibre trap to hold and manoeuvre cells combined with an orthogonally placed objective to record Raman spectra. The dual beam trap, due to its divergent light fields, offers an as yet unexploited ability to hold and move large cellular objects with reduced prospects of photodamage. We additionally show how this system permits us to move large primary human keratinocytes (approximately 30 microns in diameter), such that we may record Raman spectra from local parts of a trapped cell with ease. Finally, we develop a rudimentary microfluidic system used to generate a flow of cells. Using our dual beam trap, combined with this flow system, we hold and acquire Raman spectra from individual cells chosen from a sample of HL60 human promyelocytic leukemia cells.

Photoporation and cell transfection using a violet diode laser.

The introduction and subsequent expression of foreign DNA inside living mammalian cells (transfection) is achieved by photoporation with a violet diode laser. We direct a compact 405 nm laser diode source into an inverted optical microscope configuration and expose cells to 0.3 mW for 40 ms. The localized optical power density of ~1200 MW/m2 is six orders of magnitude lower than that used in femtosecond photoporation (~104 TW/m2). The beam perforates the cell plasma membrane to allow uptake of plasmid DNA containing an antibiotic resistant gene as well as the green fluorescent protein (GFP) gene. Successfully transfected cells then expand into clonal groups which are used to create stable cell lines. The use of the violet diode laser offers a new and simple poration technique compatible with standard microscopes and is the simplest method of laser-assisted cell poration reported to date.

Cell cytometry with a light touch: sorting microscopic matter with an optical lattice.

Lab-on-a-chip design is a key technology for increasing both the reliability and the functionality of many different preparation and diagnostic techniques in biomedicine. The drive towards ever more integrated lab-on-a-chip designs requires increasingly complex microfluidic systems. In order to build these systems, non-invasive actuators such as pumps, filters and mixers are required. We have demonstrated microfluidic sorting based on a 3D interference pattern, formed from multiple coherent laser beams, which has the potential to fulfil all the above criteria. By interfering five laser beams from a fibre laser at 1070 nm, we have formed a 3D optical lattice. When particles flow through the optical lattice their trajectories depend upon the force exerted on the particle by the optical lattice, in combination with the drag force exerted by the fluid flow. Hence, with the strength of a particle's interaction with the lattice determining the total force exerted upon it, its trajectory is determined by its physical properties. These properties include refractive index, size and shape, giving a range of criteria with which to sort an analyte. We have shown separation at 45 degrees of polymer from silica microspheres (by refractive index), the separation of protein microcapsules and the sorting of erythrocytes from lymphocytes. The interference pattern can be tailored to the particles and if a blockage occurs, the laser can simply be switched off, unlike solid-state micro-sorters, so that no jamming occurs. Efficiencies in excess of 95% have been achieved.

Chromosomal translocation in mesenchymal hamartoma of liver: what is its significance?

Mesenchymal hamartoma of the liver is generally considered to be benign in nature, and surgical excision has been the treatment of choice. There have been 3 reports on the association of cytogenetic abnormalities with this tumor, and the possibility of malignant potential has been raised. The authors report a fourth case with a previously unreported complex chromosomal translocation between chromosomes 11, 17, and 19 at bands q12, p11, and q13.3, respectively in all cells examined and discuss the significance of this finding.

Identification of poorly differentiated synovial sarcoma: a comparison of clinicopathological and cytogenetic features with those of typical synovial sarcoma.

AIMS: Poorly differentiated areas in synovial sarcomas (SS) are known to be associated with a poorer prognosis. The aim of our study was to describe the morphological spectrum of poorly differentiated synovial sarcomas (PDSS) and refine the criteria for their recognition. METHODS AND RESULTS: The clinicopathological features of 28 PDSS were compared with those of 26 classic SS. Common cell types in PDSS included epithelioid, spindle and Ewing sarcoma-like small round cells. Unusual features included presence of desmoplastic small cell tumour-like areas and extraskeletal myxoid chondrosarcoma-like areas. The presence of necrosis (P = 0.002), a mitotic rate over 10/10 high-power fields (P < 0.001), a haemangiopericytomatous vascular pattern (P < 0.001) and vascular invasion (P = 0.003) were significantly associated with PDSS, while mast cells (P < 0.001), calcification (P < 0.001) and hyaline bands (P < 0.001) were significantly associated with classic SS. Poorly differentiated areas showed increased proliferative activity with Ki67. PDSS showed a tendency to be larger (P = 0.008) and to be located in proximal more than distal sites (P = 0.025). Three entirely poorly differentiated tumours were diagnosed by demonstration of the t(X;18)(p11;q11) translocation. PDSS showed additional cytogenetic abnormalities. CONCLUSIONS: Poorly differentiated synovial sarcomas show a spectrum of histological features, which may simulate other malignant neoplasms. The diagnosis of entirely poorly differentiated synovial sarcomas requires cytogenetic analysis.

Relationship between imidazoline(2) sites and monoamine oxidase.

I(2) site-selective compounds are known to interact with and inhibit monoamine oxidase (MAO), but it remains unclear as to whether this interaction occurs through an allosteric or competitive interaction. This study used the new selective, irreversible I(2) ligand BU99006, to clarify the relationship between MAO and the I(2) binding sites (I(2)-BS). Results demonstrate that irreversible binding of BU99006 to rat brain membranes does not inhibit the enzyme or interfere with its interaction with other imidazoline enzyme inhibitors. This finding suggests that the I(2) sites that react with BU99006 are not those implicated in MAO inhibition and points to the existence of at least two distinct I(2) binding proteins.

In vivo estimation of imidazoline(2) binding site turnover.

Turnover of imidazoline(2) (I(2)) binding sites in the mouse and rat brain has been measured following an acute intravenous dose of BU99006. This ligand selectively and irreversibly knocks out I(2) sites, as defined by [(3)H]2BFI binding. Recovery was measured using radioligand binding and autoradiography to determine global and regional changes in I(2) density. The density of I(2) sites in brain recovered from BU99006 treatment with a half-life of 2.1 hours in mice and 4.3 hours in rats. Monoamine oxidase (MAO) activity and MAO binding density were unaltered in the brains of BU99006-treated animals. These data suggest that the I(2) site that reacts with BU99006 recovers rapidly and is independent of MAO.

Somatic cell nuclear transfer.

Cloning by nuclear transfer from adult somatic cells is a remarkable demonstration of developmental plasticity. When a nucleus is placed in oocyte cytoplasm, the changes in chromatin structure that govern differentiation can be reversed, and the nucleus can be made to control development to term.

Creation and manipulation of three-dimensional optically trapped structures.

An interferometric pattern between two annular laser beams is used to construct three-dimensional (3D) trapped structures within an optical tweezers setup. In addition to being fully translatable in three dimensions, the trapped structure can be rotated controllably and continuously by introducing a frequency difference between the two laser beams. These interference patterns could play an important role in the creation of extended 3D crystalline structures.

Moving interference patterns created using the angular Doppler-effect.

We use the angular Doppler-effect to obtain stable frequency shifts from below one Hertz to hundreds of Hertz in the optical domain, constituting a control of 1 part in 1014. For the first time, we use these very small frequency shifts to create continuous motion in interference patterns including the scanning of linear fringe patterns and the rotation of the interference pattern formed from a Laguerre-Gaussian beam. This enables controlled lateral and rotational movement of trapped particles.

Controlled rotation of optically trapped microscopic particles.

We demonstrate controlled rotation of optically trapped objects in a spiral interference pattern. This pattern is generated by interfering an annular shaped laser beam with a reference beam. Objects are trapped in the spiral arms of the pattern. Changing the optical path length causes this pattern, and thus the trapped objects, to rotate. Structures of silica microspheres, microscopic glass rods, and chromosomes are set into rotation at rates in excess of 5 hertz. This technique does not depend on intrinsic properties of the trapped particle and thus offers important applications in optical and biological micromachines.

Randomised trial of personalised computer based information for patients with schizophrenia.

OBJECTIVES: To compare use, effect, and cost of personalised computer education with community psychiatric nurse education for patients with schizophrenia. DESIGN: Randomised trial of three interventions. Modelling of costs of alternatives. PARTICIPANTS: 112 patients with schizophrenia in contact with community services; 67 completed the intervention. INTERVENTIONS: Three interventions of five educational sessions: (a) computer intervention combining information from patient's medical record with general information about schizophrenia; (b) sessions with a community psychiatric nurse; (c) "combination" (first and last sessions with nurse and remainder with computer). MAIN OUTCOME MEASURES: Patients' attendance, opinions, change in knowledge, and psychological state; costs of interventions and patients' use of NHS community services; modelling of costs for these three, and alternative, interventions. RESULTS: Rates of completion of intervention did not differ significantly (71% for combination intervention, 61% for computer only, 46% for nurse only). Computer sessions were shorter than sessions with nurse (14 minutes v 60 minutes). More patients given nurse based education thought the information relevant. Of 20 patients in combination group, 13 preferred the sessions with the nurse and seven preferred the computer. There were no significant differences between groups in psychological outcomes. Because of the need to transport patients to the computer for their sessions, there was no difference between interventions in costs, but computer sessions combined with other patient contacts would be substantially cheaper. CONCLUSIONS: The computer based patient education offered no advantage over sessions with a community psychiatric nurse. Investigation of computer use combined with other health service contacts would be worth while.

Trapping and manipulation of low-index particles in a two-dimensional interferometric optical trap.

We demonstrate optical trapping and manipulation of low-index spheres in two dimensions, using the pattern produced by two interfering plane waves. This technique shows, for what is believed to be the first time, alignment of an array of hollow spheres and simultaneous manipulation of high- and low-index particles in the horizontal plane. Furthermore, rodlike particles (up to 30microm in length) are manipulated simultaneously with the low-index particles. This technique offers a practical method for manipulating bubbles, low-index droplets, or rodlike biological samples.