Evaluation of a Novel Non-Competitive Antagonist as a Radioligand for the N-Methyl-D-Aspartate Receptor-Channel Complex In Vivo

This thesis reports the synthesis and initial evaluation of the substituted guanidine N-(l- Napthyl)-N'-(2-iodophenyl)-N'-methylguanidine (CNS 1261) as a potential agent to image N-methyl-D-aspartate (NMDA) receptor activation in vivo. The pharmacology of unlabelled CNS 1261 was investigated in vitro using ligand binding assays and in vivo using autoradiographic procedures. Investigations were designed to examine the ability of CNS 1261 to inhibit radioligand binding to the NMDA receptor and to other neurotransmitter receptors. [14C]2-deoxyglucose autoradiography was used to measure local rates of glucose utilisation following systemic administration of CNS 1261. The effects of CNS 1261 on glucose utilisation were compared to those obtained in a previous study carried out by Kurumaji et al (1989) using MK801. Secondly, in order to assess the ability of [125I]CNS 1261 to measure levels of NMDA receptor activation in the brain, a modification of the [125I]MK801 in vivo binding technique described by McCulloch et al (1992) was used to investigate the uptake and retention of [125I]CNS 1261 in the normal rat brain. The pattern of[125I]CNS 1261 uptake was compared to that of [125I]MK801 in parallel experiments. Finally, autoradiographic techniques were used to assess the utility of [125I]CNS 1261 in imaging changes in NMDA receptor activation in vivo. NMDA receptor activation was manipulated via proton blockade and microinjection of the excitatory amino acid agonist NMDA into the cortex Pharmacology of CNS 1261 The ability of CNS 1261 to inhibit [3H]MK801 binding was investigated in crude synaptic rat brain membranes (Cambridge NeuroScience Inc.). CNS 1261 (10muM) binds to the NMDA receptor in vitro with high affinity (Ki = 25nM for displacing [3H]MK801 binding). The effects of unlabelled CNS 1261 (l0nM and 1muM) on the binding of ligands to the NMDA receptor and to other neurotransmitter receptors was more extensively investigated by submitting the compound for commercial screening (Novascreen). CNS 1261 (1?M) was extremely selective showing activity (99% inhibition) only in the [3H]MK801 binding assay. The effects of CNS 1261 (1, 3 and l0mg/kg) on local cerebral glucose use were examined in the conscious lightly restrained rat. The systemic administration of CNS 1261 resulted in overt behavioural responses and marked alterations in glucose use within the central nervous system. Administration of CNS 1261 produced highly circumscribed changes in glucose utilisaion that could be readily visualised on autoradiograms. Decreases in glucose use (approximately 30%) were observed in layer IV of the frontal, sensory-motor and auditory cortices and in the inferior colliculus. Distinct, significant elevations in glucose use were observed in the hippocampus molecular layer, dentate gyrus, limbic system (posterior cingulate cortex, caudal entorhinal cortex, mamillary body, anteroventral thalamus), retrosplenial cortex and the myelinated fiber tract of the fornix. Correlation analysis revealed that the overall pharmacological effects of CNS 1261 were extremely similar to the overall effects of MK801, correlation coefficient, r = 0.87. Subtle differences were observed in a number of regions. A greater number of regions displayed extreme sensitivity to CNS 1261 than to MK801, such as the anteroventral thalamus, mamillary body and inferior colliculus. In contrast, the entorhinal cortex was much less sensitive to CNS 1261 than to MK801 [125I]CNS 1261 uptake in the normal rat brain Radio-iodinated (125I or 123I)CNS 1261 was synthesised at high specific activity (>2000Ci/mmol) and chemical purity (>97%) at the West of Scotland Radionuclide Dispensary, Glasgow. Investigation of the in vivo uptake and retention of [125I]CNS 1261 was carried out in halothane anaesthetised rats. The initial uptake of [125I]CNS 1261 reflected cerebral blood flow. At time points beyond 30 minutes the uptake of [125I]CNS 1261 reflected the classical pattern of NMDA receptor distribution with the highest levels of binding in the hippocampus and low levels in the hypothalamus and cerebellum. At 120 minutes, [125I]CNS 1261 uptake within hippocampal regions relative to that in the cerebellum (a measure of non-specific binding) was 70-140% greater than that observed with [125I]|MK801. The mechanisms underlying the superior imaging capability of [125I]CNS 1261 was addressed by investigation of the lipophilicity and metabolism of this tracer. (Abstract shortened by ProQuest.)

Supporting parents with learning disabilities in Scotland : Challenges and opportunities

The Scottish Government wants to improve the lives of people with learning disabilities. This report is one of a series commissioned by the Scottish Commission for Learning Disability on behalf of the Scottish Government to understand how we can achieve this. Scotland’s learning disability strategy, The keys to life, is based on a commitment to human rights, and seeks to improve the quality of life for people with learning disabilities so that they live longer, healthier lives, participate fully in all aspects of society and prosper as individuals. People with learning disabilities should have the same rights to family life as anyone else and supporting parents with learning disabilities has a crucial role to play in making those rights real. As this report demonstrates, people with learning disabilities face a myriad of challenges when they become parents. People with learning disabilities can and do become good parents. However, they may require additional support to to become the best parents they can be. That support needs to be flexible. It will often need to be long term and intensive, particularly at key stages of a child’s development. To be effective it has to be built around the needs of the whole family. The Scottish Commission for Learning Disability has recently refreshed the Scottish Good Practice Guidelines for Supporting Parents with Learning Disabilities. This report maps the range of services available now and explores the extent to which parents with learning disabilities have access to services based on the principles of supported parenting. It sets out clear thinking and detailed recommendations about providing support which reflects those guidelines, consistent recording across health and social care to ensure early identification and awareness raising. This will ensure good practice is adopted and embedded. This will require close working with Integration Joint Boards and collaborative working across sector boundaries. Early identification and intervention is key to avoiding a crisis model of intervention which parents with learning disabilities have all too often experienced in the past. Through our involvement in the Working Together with Parents Network, a collaboration with Learning Disability Wales and the Norah Fry Centre for Disability Studies at the University of Bristol, funded by the Esmee Fairburn Foundation, we will continue to drive improved policy and practice. This report provides an invaluable evidence base for that work. Our objective must be to use every available opportunity to support parents with learning disabilities to secure better outcomes for them and their childre

General public awareness and views of community pharmacy services in Scotland: the 'first port of call' study.

Background: The recently published 'Achieving Excellence in Pharmaceutical Care: a Strategy for Scotland' urges community pharmacy (CP) to make itself the 'first port of call' for healthcare advice. Purpose: To explore the Scottish general public's awareness of CP services and their openness to consider CP their 'first port of call' for health care advice. Methods: A Scotland-wide survey was administered up to 20 times in each of 117 CPs by pre-registration pharmacy graduates. It included Likert scales of attitudinal statements with items developed from existing literature. Ethical approval had been gained. Results: To date, the 2260 surveys have been completed from 117 CPs giving a response rate of 96.5%. Varying ages and standards of health are represented. Respondents were aware CPs 'are contracted to the NHS' (87.4%) and that 'pharmacists with an additional qualification can diagnose and prescribe' (53.3%). 87.6% would likely/very likely view CP as their 'First port of Call' for common illnesses. However, 71.4% were unlikely/very unlikely to approach CP with 'more serious symptoms'. Intentions for 'monitor or review of regular medicines' were less clear (unlikely/very unlikely (38.2%) against likely/very likely (35.1%)). 44% lacked an awareness of CP services in general. 75.3% indicated the pharmacist 'should have access to read and update relevant parts of my electronic health record' and pharmacist access to electronic records would make 67.8% more likely to view CP as a 'first port of call' for health issues. Conclusions: This Scotland-wide survey indicated the general public's positivity and openness to access community pharmacy services, however, being recognised as a 'First Port of Call' may require awareness raising

Desacetyl-α-melanocyte stimulating hormone and α-melanocyte stimulating hormone are required to regulate energy balance.

OBJECTIVE: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood. Desacetyl-α-MSH is considered to be unimportant for regulating energy balance despite being more potent (compared with α-MSH) at activating the appetite-regulating MC4R in vitro. Thus, the physiological role for desacetyl-α-MSH is still unclear. METHODS: We created a novel mouse model to determine whether desacetyl-α-MSH plays a role in regulating energy balance. We engineered a knock in targeted QKQR mutation in the POMC protein cleavage site that blocks the production of both desacetyl-α-MSH and α-MSH from adrenocorticotropin (ACTH1-39). RESULTS: The mutant ACTH1-39 (ACTHQKQR) functions similar to native ACTH1-39 (ACTHKKRR) at the melanocortin 2 receptor (MC2R) in vivo and MC4R in vitro. Male and female homozygous mutant ACTH1-39 (Pomctm1/tm1) mice develop the characteristic melanocortin obesity phenotype. Replacement of either desacetyl-α-MSH or α-MSH over 14 days into Pomctm1/tm1 mouse brain significantly reverses excess body weight and fat mass gained compared to wild type (WT) (Pomcwt/wt) mice. Here, we identify both desacetyl-α-MSH and α-MSH peptides as regulators of energy balance and highlight a previously unappreciated physiological role for desacetyl-α-MSH. CONCLUSIONS: Based on these data we propose that there is potential to exploit the naturally occurring POMC-derived peptides to treat obesity but this relies on first understanding the specific function(s) for desacetyl-α-MSH and α-MSH

Common, low-frequency, rare, and ultra-rare coding variants contribute to COVID-19 severity

The combined impact of common and rare exonic variants in COVID-19 host genetics is currently insufficiently understood. Here, common and rare variants from whole-exome sequencing data of about 4000 SARS-CoV-2-positive individuals were used to define an interpretable machine-learning model for predicting COVID-19 severity. First, variants were converted into separate sets of Boolean features, depending on the absence or the presence of variants in each gene. An ensemble of LASSO logistic regression models was used to identify the most informative Boolean features with respect to the genetic bases of severity. The Boolean features selected by these logistic models were combined into an Integrated PolyGenic Score that offers a synthetic and interpretable index for describing the contribution of host genetics in COVID-19 severity, as demonstrated through testing in several independent cohorts. Selected features belong to ultra-rare, rare, low-frequency, and common variants, including those in linkage disequilibrium with known GWAS loci. Noteworthily, around one quarter of the selected genes are sex-specific. Pathway analysis of the selected genes associated with COVID-19 severity reflected the multi-organ nature of the disease. The proposed model might provide useful information for developing diagnostics and therapeutics, while also being able to guide bedside disease management. © 2021, The Author(s)

Genetic mechanisms of critical illness in COVID-19.

Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials